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第 1 条,共 344 条
标题: High Quality, Mass-Producible Semipolar GaN and InGaN Light-Emitting Diodes Grown on Sapphire
作者: Song, J (Song, Jie); Han, J (Han, Jung)
来源出版物: PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS 文献号: 1900565 DOI: 10.1002/pssb.201900565 提前访问日期: DEC 2019
摘要: The heteroepitaxy efforts of semipolar and nonpolar GaN grown on foreigner substrates are reviewed and summarized in the past 20 years. With the demonstration of three representative semipolar GaN grown on sapphire, the capability to produce semipolar GaN with any orientation on sapphire is exhibited. Also, a unique growth technology called facet-engineered orientation-controlling growth to eliminate the stacking faults (SFs) in semipolar GaN is developed and SF-free (202 over bar 1) GaN grown on sapphire is presented, demonstrating the capability of producing device-quality, large-area semipolar GaN. InGaN green light-emitting diodes (LEDs) grown on the SF-free semipolar (202 over bar 1) GaN/sapphire templates are performed with much higher external quantum efficiency in comparison with the typical semipolar/nonpolar LEDs heteroepitaxially grown on foreigner substrates reported before.
入藏号: WOS:000502944200001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Song, Jie                  0000-0001-6245-2879

ISSN: 0370-1972
eISSN: 1521-3951
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第 2 条,共 344 条
标题: Planar and ridge waveguides in Yb3+-doped silicate glasses fabricated by proton implantation and precise diamond blade dicing
作者: Zhang, J (Zhang, Jie); Guo, WT (Guo, Wen-Tao); Tang, CY (Tang, Chen-Yang); Yan, S (Yan, Sen); Li, WN (Li, Wei-Nan); Liu, CX (Liu, Chun-Xiao)
来源出版物: OPTICS COMMUNICATIONS 卷: 453 文献号: UNSP 124344 DOI: 10.1016/j.optcom.2019.124344 出版年: DEC 15 2019
摘要: We firstly report on the planar waveguide via the single-energy proton implantation in the Yb3+-doped silicate glass. The implanted energy and fluence are 400 keV and 8.0x10(16) ions/cm(2), respectively. The thermal treatment at 200 degrees C for lh was used to optimize waveguiding characteristics. The guided-mode spectra in the planar waveguide before and after annealing were characterized by the m-line method at 632.8 and 1539 nm. The distributions of refractive index for the as-implanted and annealed planar waveguides were reconstructed by the reflectivity calculation method. The optical characterizations were conducted at 632.8 nm using the end-fire coupling method before and after the thermal treatment. Then, the ridge waveguide was formed by the precise diamond blade dicing on the annealed planar Yb3+-doped silicate glass waveguide. The microscope image and near-field intensity profile of the ridge waveguide were investigated by the metallographic microscope and the end-face coupling system, respectively.
入藏号: WOS:000487257300015
ISSN: 0030-4018
eISSN: 1873-0310
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第 3 条,共 344 条
标题: Experimental demonstration of wave-front coded imaging with a very low response of the modulation transfer function at the Nyquist frequency
作者: Zhao, H (Zhao, Hui); Mi, J (Mi, Jiao); Yu, CC (Yu, Congcong); Ge, R (Ge, Rui); Fan, XW (Fan, Xuewu)
来源出版物: APPLIED OPTICS 卷: 58 期: 35 页: 9562-9569 DOI: 10.1364/AO.58.009562 出版年: DEC 10 2019
摘要: Wave-front coding (WFC) is a well-known technique that can be used to extend the depth of field (DOF) of incoherent imaging systems. The phase masks make the optical transfer function drop significantly, and digital restoration must be used to obtain a clear image with a largely extended DOF. According to the existing literature, in order to obtain satisfactory restoration results, the optical modulation transfer function (MTF) at the Nyquist frequency is required to be bigger than 0.1, which has already become a popularly accepted design constraint. However, according to our experimental research reported in this paper, this requirement is overly strict. By assembling one already fabricated WFC lens and another camera having physically higher resolution, the MTF of the newly assembled WFC system used in the experimentation has quite a low response at its Nyquist frequency. The experimental results demonstrate that when the optical MTF value at the Nyquist frequency reaches the minimum value of about 0.05, visually satisfactory restoration results can still be obtained as long as the MTF is optimized to be highly insensitive to defocus and the corresponding SNR of the coded intermediate images goes beyond 20 dB at the same time. The experimental results indicate that the overly strict constraint could be alleviated while designing a WFC system. (C) 2019 Optical Society of America
入藏号: WOS:000502086200010
PubMed ID: 31873560
ISSN: 1559-128X
eISSN: 2155-3165
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第 4 条,共 344 条
标题: Master oscillator pulse nonlinear amplifier system based on all polarization-maintaining fiber
作者: Zhang, T (Zhang Tong); Zhang, WG (Zhang Wei-Guang); Cai, YJ (Cai Ya-Jun); Hu, XH (Hu Xiao-Hong); Feng, Y (Feng Ye); Wang, YS (Wang Yi-Shan); Yu, J (Yu Jia)
来源出版物: ACTA PHYSICA SINICA 卷: 68 期: 23 文献号: 234204 DOI: 10.7498/aps.68.20190925 出版年: DEC 5 2019
摘要: The erbium-doped fiber oscillators, especially mode-locked fiber oscillators for generating femtosecond pulses, cannot meet the requirements for most of modern industrial applications because they are resticted by the low power and the limited wavelength range. In order to solve this problem, lots of efforts have been made both theoretically and experimentally, to improve the chirped pulse amplification (CPA) technology. The emergence of CPA technology greatly enhances the energy of laser pulses. The broadening and compressing of the laser pulses are both always dependent on the improving of spatial optical components, such as grating pairs. However, the use of this kind of method can increase the complexity of the amplification system to a certain extent. This may be an essential reason why more and more researchers pay attention to all fiber amplification system. In this paper, the master oscillator pulse nonlinear amplifier system based on all polarization- maintaining fiber is proposed, which is mainly composed of an oscillator based on the semiconductor saturable absorption mirror and linear cavity, a two-stage amplification and a pulse compressor constructed by a single-mode conductive fiber with anomalous dispersion. Using this system, we obtain ultrashort laser pulses in the 1.5 nm band whose pulse width equals 44 fs and single pulse energy reaches about 1 nJ. The system is not only compact and miniaturized but also stable and reliable due to the all polarization-maintaining fiber. Subsequently, an MgO doped periodically poled lithium niobite crystal with a thickness of 1 mm is used to implement frequency doubling. The pulses from the system are accurately focused on a position where the crystal polarization period is 19.8 mu m with help of some wave plates and lenses. Adjusting the optical path reasonably and optimizing colliminated focusing parameters, the double-frequency pulse output with certral wavelength of 779 nm and average power of 60 W is obtained, in which the conversion efficiency reaches 30%. The result shows that the master oscillator pulse nonlinear amplifier system based on all polarization maintaining fiber can produce satisfactory ultrashort pulses. It is a new idea for generating the ultrashort femtosecond pulses in the near-infrared band.
入藏号: WOS:000501344000014
ISSN: 1000-3290
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第 5 条,共 344 条
标题: Controlled Asymmetric Bidirectional Hybrid of Remote State Preparation and Quantum Teleportation
作者: Huo, GW (Huo, Guang-Wen); Zhang, TY (Zhang, Tong-Yi); Zha, XW (Zha, Xin-Wei); Zhang, MZ (Zhang, Mei-Zhi)
来源出版物: INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS DOI: 10.1007/s10773-019-04326-x 提前访问日期: DEC 2019
摘要: We propose a protocol of Asymmetric implementing controlled joint remote state preparation and meanwhile realizing controlled quantum teleportation. That is to say, Alice wants to teleport an arbitrary two-qubit state to Bob, and Bob wants to remotely prepare a known state for Alice via the control of supervisors Charlie. Compared with previous studies for the schemes of solely bidirectional quantum teleportation, the new protocol is a kind of hybrid approach of information communication which makes the quantum channel multipurpose.
入藏号: WOS:000501160300002
ISSN: 0020-7748
eISSN: 1572-9575
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第 6 条,共 344 条
标题: Structured active fiber fabrication and characterization of a chemically high-purified Dy3+-doped chalcogenide glass
作者: Xiao, XS (Xiao, Xusheng); Xu, YT (Xu, Yantao); Cui, J (Cui, Jian); Liu, XG (Liu, Xiaogang); Cui, XX (Cui, Xiaoxia); Wang, XS (Wang, Xunsi); Dai, SX (Dai, Shixun); Guo, HT (Guo, Haitao)
来源出版物: JOURNAL OF THE AMERICAN CERAMIC SOCIETY DOI: 10.1111/jace.16921 提前访问日期: DEC 2019
摘要: By conventional melt-quenching techniques, a series of Dy3+-doped (0.1 to 1.0 wt%) Ga5Ge20Sb15S60 bulk glasses were fabricated and their potential for developing mid-infrared fiber laser beyond 4 mu m were evaluated, in which the optimal Dy3+ doping concentration was found to be 0.3 wt% and the largest laser quality factor value (sigma(e) x tau(mea) = 2.62 x 10(-23) cm(2) s) among all of the Dy3+-doped chalcogenide glass was obtained. On this basis, through using the chemical purification methods with chlorine gas combined with the dynamic distillation process, the high-purity GGSS glasses with low O-H and S-H absorptions were successfully fabricated, which was confirmed by the optimized mid-infrared linear transmittance and improved fluorescent lifetimes of Dy3+: H-6(13/2), H-6(11/2) levels. Furthermore, for the first time to the best of our knowledge, the Dy3+-doped, single-mode, and double-cladding chalcogenide fibers with the core/cladding ratios of 125:60:11 and 125:66:11.5 were achieved by a multistage rod-in-tube fiber drawing process and extrusion methods, respectively. The GeS2-based fiber exhibits excellent transmission performance at 1.0-5.0 mu m: 3.0 dB/m at 2.9 mu m (O-H), 2.4 dB/m at 4.1 mu m (S-H). Combining the advantages of high-purity, high doping concentration and single-mode double-cladding structure, the optimized active fiber should be an ideal efficient and low-threshold medium toward mid-infrared fiber laser beyond 4 mu m.
入藏号: WOS:000500577200001
ISSN: 0002-7820
eISSN: 1551-2916
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第 7 条,共 344 条
标题: 1D Solitons in Saturable Nonlinear Media with Space Fractional Derivatives
作者: Shi, JC (Shi, Jincheng); Zeng, JH (Zeng, Jianhua)
来源出版物: ANNALEN DER PHYSIK 文献号: 1900385 DOI: 10.1002/andp.201900385 提前访问日期: DEC 2019
摘要: Two decades ago, standard quantum mechanics entered into a new territory called space-fractional quantum mechanics, in which wave dynamics and effects are described by the fractional Schrodinger equation. Such territory is now a key and hot topic in diverse branches of physics, particularly in optics driven by the recent theoretical proposal for emulating the fractional Schrodinger equation. However, the light-wave propagation in saturable nonlinear media with space fractional derivatives is yet to be clearly disclosed. Here, such nonlinear optics phenomenon is theoretically investigated based on the nonlinear fractional Schrodinger equation with nonlinear lattices-periodic distributions of either focusing cubic (Kerr) or quintic saturable nonlinearities-and the existence and evolution of localized wave structures allowed by the model are addressed. The model upholds two kinds of one-dimensional soliton families, including fundamental solitons (single peak) and higher-order solitonic structures consisting of two-hump solitons (in-phase) and dipole ones (anti-phase). Notably, the dipole solitons can be robust stable physical objects localized merely within a single well of the nonlinear lattices-previously thought impossible. Linear-stability analysis and direct simulations are executed for both soliton families, and their stability regions are acquired. The predicted solutions can be readily observed in optical experiments and beyond.
入藏号: WOS:000500415500001
ISSN: 0003-3804
eISSN: 1521-3889
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第 8 条,共 344 条
标题: Low-Threshold 4/5 Octave-Spanning Mid-Infrared Frequency Comb in a LiNbO3 Microresonator
作者: Fan, WC (Fan, Weichen); Lu, ZZ (Lu, Zhizhou); Li, W (Li, Wei); Wang, XY (Wang, Xinyu); Zhou, MY (Zhou, Mengyao); Wang, WQ (Wang, Weiqiang); Sun, QB (Sun, Qibing); Wang, GX (Wang, Guoxi); Cheng, D (Cheng, Dong); Wang, LR (Wang, Leiran); Zhang, WF (Zhang, Wenfu); Zhao, W (Zhao, Wei)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 6 文献号: 6603407 DOI: 10.1109/JPHOT.2019.2949313 出版年: DEC 2019
摘要: Mid-infrared (MIR) optical frequency combs (OFCs) are ideal light sources for precision metrology and can find extensive applications, especially in molecular spectroscopy and gas detection. Here the generation of mode-locked MIR frequency comb in a LiNbO3 microring through optimized slot-waveguide design is proposed. Such microcomb can span over four-fifths of an octave (ranging from similar to 2810 nm to similar to 4630 nm) with pump power as low as 50 mW, which can be applied to the 2f-3f self-referencing for fully stabilization and helpful to monolithic integration of the whole system. Further investigations on complex dynamical processes for the microcomb generation suggest that the intracavity soliton drifting caused by the third-order dispersion could be compensated by the self-steepening effect as introducing an additional drift through proper dispersion tailoring. This work could facilitate the low-threshold broadband MIR frequency comb generation technique, as well as provide a way to realize more delicate control of soliton microcombs in both temporal and spectral domain.
入藏号: WOS:000502033100001
ISSN: 1943-0655
eISSN: 1943-0647
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第 9 条,共 344 条
标题: Optimization of temporal gate by two-color chirped lasers for the generation of isolated attosecond pulse in soft X rays
作者: He, LW (He, Liwei); Yuan, GL (Yuan, Guanglu); Wang, K (Wang, Kan); Hua, WJ (Hua, Weijie); Yu, C (Yu, Chao); Jin, C (Jin, Cheng)
来源出版物: PHOTONICS RESEARCH 卷: 7 期: 12 页: 1407-1415 DOI: 10.1364/PRJ.7.001407 出版年: DEC 1 2019
摘要: We propose a simple and efficient method to optimize two-color chirped laser pulses by forming a "temporal gate" for the generation of isolated attosecond pulses (IAPs) in soft X rays. We show that the generation process for higher and cutoff harmonics can be effectively limited within the temporal gate, and the harmonic emission interval can be further reduced with the help of phase-matching by only selecting the contribution from short-trajectory electrons. This two-color gating mechanism is verified by increasing the pulse duration, raising the gas pressure, and extending the target cutoff. Compared to the five-color waveform in Phys. Rev. Lett. 102, 063003 (2009), our waveform can be used to generate the IAP in the long-duration laser pulse while the cutoff energy is higher without the reduction of harmonic yields. Our work provides an alternative temporal gating scheme for the generation of IAPs by simultaneously improving the harmonic conversion efficiency, thus making the attosecond soft X rays an intense and highly time-resolved tabletop light source for future applications. (C) 2019 Chinese Laser Press
入藏号: WOS:000500910500008
ISSN: 2327-9125
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第 10 条,共 344 条
标题: Ultrahigh-Q toroidal dipole resonance in all-dielectric metamaterials for terahertz sensing
作者: Chen, X (Chen, Xu); Fan, WH (Fan, Wenhui)
来源出版物: OPTICS LETTERS 卷: 44 期: 23 页: 5876-5879 DOI: 10.1364/OL.44.005876 出版年: DEC 1 2019
摘要: By arranging two pairs of high-index dielectric disks into a unit cell, a novel, to the best of our knowledge, terahertz metamaterials sensor integrated with a microfluidic channel is proposed. With the introduction of a new way of symmetry breaking in the unit cell, the strong toroidal dipole response with ultrahigh- Q is excited and investigated, which is related to the existence of the trapped mode. The simulation results show that the calculated quality factor and the corresponding figure of merit (FoM) of this sensor can reach 3189 and 515, respectively. These advantages allow for the proposed structure to have potential applications in high-performance gases, liquids, and biological materials sensing. (C) 2019 Optical Society of America
入藏号: WOS:000499141000059
PubMed ID: 31774802
ISSN: 0146-9592
eISSN: 1539-4794
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第 11 条,共 344 条
标题: Single-Photon Reflectivity and Depth Imaging by Continuous Measurement of Arrival Time of Photons
作者: Yan, QR (Yan, Qiurong); Li, D (Li, Dan); Wang, YF (Wang, Yifan); Yang, YB (Yang, Yibing); Tang, LN (Tang, Linao); Wang, YH (Wang, Yuhao)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 6 文献号: 6901914 DOI: 10.1109/JPHOT.2019.2945989 出版年: DEC 2019
摘要: We demonstrate a reflectivity and depth imaging Lidar system based on a novel photon arrival time measurement method. In this method, the arrival time of photons in a scanning position is continuously measured with a common starting point. The number of laser pulses is counted by a specially designed field programmable gate array (FPGA) control module as the coarse time of arrival photon. Time interval between arrival photon and the nearest coming laser pulse is measured by a time-correlated single-photon counting (TCSPC) module as the fine time of arrival photon. Using the system, not only the single-photon counting imaging can be realized, but also the first photon imaging, the first two photons imaging, etc. can be realized. A photon statistical model based on the doubly stochastic Poisson point processes, a time-gated filtering algorithm, and the reflectivity algorithm based on maximum likelihood estimation are derived. High-sensitivity reflectivity and depth imaging with a resolution of 512 x 512 pixels are achieved. The experimental results show that the horizontal spatial resolution is 2 mm, the vertical depth resolution is 5.375 cm, and the average number of photons per pixel is less than 1.3 photons.
入藏号: WOS:000497769500001
ISSN: 1943-0655
eISSN: 1943-0647
________________________________________
第 12 条,共 344 条
标题: Research on active polarization imaging experiments and key technologies in smoke and dust environment
作者: Xie, ML (Xie, Meilin); Liu, P (Liu, Peng); Ma, CW (Ma, Caiwen); Hao, W (Hao, Wei); Huang, W (Huang, Wei); Lian, XZ (Lian, Xuezheng); Li, ZG (Li, Zhiguo); Han, JF (Han, Junfeng)
来源出版物: OPTIK 卷: 198 文献号: UNSP 163309 DOI: 10.1016/j.ijleo.2019.163309 出版年: DEC 2019
摘要: For realizing the engineering application of key technologies in the long-range active polarization imaging system, an experimental platform is built to study the static active polarization imaging technology and related image fusion algorithm in the smoke and dust environment. In the experiments, 532 nm CW laser is used as illumination source after collimation and beam expansion, metal bullet model is used as detection target, smoke environment is created through smoke generator in organic glass hood, polarization direction can be rotated by the polarizer, the images are collected by Lumerera-LM135 camera. The analysis and handling on the images are conducted by the use of the MATLAB software. In the aspects of image information entropy, average gradient, spatial frequency and standard deviation, the polarization imaging effects in various environments are quantitatively compared and analyzed, and the imaging advantages of laser illumination and polarization imaging technology in smoke and dust environment and dim conditions are verified. In order to further improve the imaging quality of active polarization imaging technology, a polarization image fusion algorithm based on fuzzy adaptive is proposed after analyzing a large number of data acquired in the experiment.
The experimental results show that the active polarization imaging technology and the improved image fusion algorithm can improve the detection distance of optical system and image contrast, expand the digestible information of images for the long-range dim target imaging in low visibility environment, and provide important data reference and technology support for the application of this technology in shooting range.
入藏号: WOS:000494480200054
ISSN: 0030-4026
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第 13 条,共 344 条
标题: Application of Gaussian fitting to the fast search of pulsar periodic
作者: Xu, N (Xu, Neng); Sheng, LZ (Sheng, Lizhi); Chen, C (Chen, Chen); Li, Y (Li, Yao); Su, T (Su, Tong); Zhao, BS (Zhao, Baosheng); Zheng, W (Zheng, Wei); Liu, CL (Liu, Chunliang)
来源出版物: OPTIK 卷: 198 文献号: UNSP 163253 DOI: 10.1016/j.ijleo.2019.163253 出版年: DEC 2019
摘要: In this paper, we provided a Gaussian fitting method for fast periodic search to improve the accuracy of chi-square method. And this method can be used for the pulse periodic search of X-ray Pulsar. Firstly, we built the fast search model based on the epoch folding procedure by employing the basic principle of the chi-square evaluation. Secondly, we simulated the distribution of chi-square value by applying the pulsar profile to the fast search model, and it is fitting well with the Gaussian function. Finally, the designed experiments indicated that applying Gaussian fitting to chi-square method can significantly improve period search accuracy.
入藏号: WOS:000494480200040
ISSN: 0030-4026
________________________________________
第 14 条,共 344 条
标题: Experimental Studies on the Noise Properties of the Harmonics From a Passively Mode-Locked Er-Doped Fiber Laser
作者: Song, JZ (Song, Jiazheng); Hu, XH (Hu, Xiaohong); Wang, HS (Wang, Hushan); Duan, T (Duan, Tao); Wang, YS (Wang, Yishan); Liu, YS (Liu, Yuanshan); Zhang, JG (Zhang, Jianguo)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 6 文献号: 1504911 DOI: 10.1109/JPHOT.2019.2937324 出版年: DEC 2019
摘要: We experimentally investigate the noise properties of a homemade 586 MHz mode-locked laser (MLL). The variation of the timing jitter versus the harmonic order is measured, which is consistent with the theoretical analyses. The dominant contributions to the timing jitter are detailedly studied by analyzing the phase noises at different harmonic frequencies. For low-order harmonics, the intensity noise and relative-intensity-noise-coupled (RIN-coupled) jitter mainly contribute to the timing jitter, while for high-order harmonics, the amplified spontaneous emission (ASE) noise makes the dominant contribution. Then we find that a higher output ratio has an obvious improvement on reducing the timing jitter and suppressing the phase noise because of the shorter pulse duration and lower net cavity dispersion caused by the higher output ratio. Finally a comparison of the noise performance between the MLL and a commercial signal generator is made, which shows that the optically generated radio-frequency signal (OGRFS) has a lower phase noise at high offset frequencies, however the higher phase noise at low offset frequencies leads to a higher timing jitter than the commercial SG.
入藏号: WOS:000494460400001
ISSN: 1943-0655
eISSN: 1943-0647
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第 15 条,共 344 条
标题: Photochromic effect of transparent lead-free ferroelectric KSr2Nb5O15 ceramics
作者: Cao, SY (Cao, Shuyao); Gao, F (Gao, Feng); Xu, J (Xu, Jie); Zhu, JH (Zhu, Jihong); Chen, Q (Chen, Qian); Guo, YT (Guo, Yiting); Li, LL (Li, Leilei); Liu, JT (Liu, Junting); Gao, T (Gao, Tong); Pawlikowska, E (Pawlikowska, Emilia); Szafran, M (Szafran, Mikolaj); Cheng, GH (Cheng, Guanghua)
来源出版物: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY 卷: 39 期: 16 页: 5260-5266 DOI: 10.1016/j.jeurceramsoc.2019.08.009 出版年: DEC 2019
摘要: Transparent KSr2Nb5O15 (KSN) lead-free ferroelectric ceramics have been synthesized via modified pressureless sintering method. A significant photochromic effect was observed for the transparent KSN ceramics prepared without rare-earth dopant modification. The piezoelectric properties depend on the grain orientations were investigated. The optical transmittance of the KSN ceramics is greater than 40% in the wavelength range of 530-800 nm. After NUV irradiation, the absorbance was enhanced by more than 40% in a broad visible range (more than 79%). The absorbance returned to the initial value after a thermal bleaching process. The results of the cycling tests and response experiments showed the stability and saturation of the photochromic effect. In addition, the possible photochromic mechanism of the KSN ceramics is discussed and the photochromic centers are identified. This transparent KSN ceramics exhibits an obvious photochromic effect and is a potential candidate materials for optical data storage and information recording applications.
入藏号: WOS:000488140300018
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chen, Qian                  0000-0002-7193-0411

ISSN: 0955-2219
eISSN: 1873-619X
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第 16 条,共 344 条
标题: Influences of group velocity dispersion on ultrafast pulse shaping in time lens
作者: Xie, P (Xie, Peng); Wen, Y (Wen, Yu); Wan, ZS (Wan, Zishen); Wang, YS (Wang, Yishan)
来源出版物: PHYSICA SCRIPTA 卷: 94 期: 12 文献号: 125503 DOI: 10.1088/1402-4896/ab33d0 出版年: DEC 2019
摘要: Time-lens technology is of significant interest in signal processing and optical communication. The impacts of group velocity dispersion (GVD) on ultrafast pulse shaping in a time-lens system based on four-wave mixing are explored in this paper. The output signals of temporal magnification and time-to-frequency conversion under different GVDs are theoretically investigated in detail. The simulation results imply that the femtosecond pulse is sensitive to GVD in propagation. GVD has an important effect on nonlinear parametric processes, which results in output signals presenting different pulse shapes and different frequency profiles. Furthermore, a model of silicon nitride waveguide with flat dispersion is proposed by finite element method and signal processing with negligible pulse distortion is realized in near-infrared region.
入藏号: WOS:000484753200003
ISSN: 0031-8949
eISSN: 1402-4896
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第 17 条,共 344 条
标题: Effect of cation vacancies on the optical and dielectric properties of KSr2Nb5O15: A first-principles study
作者: Chen, Q (Chen, Qian); Gao, F (Gao, Feng); Xu, J (Xu, Jie); Wu, CY (Wu, Changying); Cao, SY (Cao, Shuyao); Guo, YT (Guo, Yiting); Pawlikowska, E (Pawlikowska, Emilia); Szafran, M (Szafran, Mikolaj); Cheng, GH (Cheng, Guanghua)
来源出版物: JOURNAL OF THE AMERICAN CERAMIC SOCIETY DOI: 10.1111/jace.16909 提前访问日期: NOV 2019
摘要: Using first-principles calculations, the effect of cation vacancies on the electronic structures and optical characters of KSr2Nb5O15 (KSN) lead-free ferroelectrics are investigated. The calculated dielectric properties are demonstrated by the experimental results. The cation vacancies involve K+ vacancies (KSN-K), Sr2+ vacancies (KSN-Sr), and coexisting K+ and Sr2+ vacancies (KSN-K&Sr). When these cation vacancies exist in KSN, the unit cell volumes decrease, leading to phase transition from tetragonal to orthorhombic, and the cation vacancies show strong effects on the band gap of KSN, declining by 1.46%-9.46%. The optical properties including the static dielectric constants, refraction, and extinction coefficient of KSN-K, KSN-Sr, and KSN-K&Sr increase more than those of KSN without vacancies, but the reflectivity and loss function decrease. All structures with cation vacancies are mainly refractive in the 0-4 eV photon energy range and are reflective at 5-8 eV. The refractivity increases and reflectivity decreases after vacancies occur. KSN-Sr has the largest static dielectric constant while KSN-K&Sr has the smallest values. The dielectric constant can be adjusted in the range of 25% by controlling the cation vacancies. The calculated dielectric properties are in good agreement with the experimental results. The results pave the way to regulate the optical and dielectric properties of lead-free ferroelectrics by controlling different cation vacancies.
入藏号: WOS:000499114200001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chen, Qian                  0000-0002-7193-0411

ISSN: 0002-7820
eISSN: 1551-2916
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第 18 条,共 344 条
标题: Toroidal metasurfaces integrated with microfluidic for terahertz refractive index sensing
作者: Chen, X (Chen, Xu); Fan, WH (Fan, Wenhui)
来源出版物: JOURNAL OF PHYSICS D-APPLIED PHYSICS 卷: 52 期: 48 文献号: 485104 DOI: 10.1088/1361-6463/ab3ea0 出版年: NOV 27 2019
摘要: A terahertz refractive index sensor consisting of toroidal dipole resonance metasurface integrated with microfluidic channel is proposed. The excitation of toroidal dipole resonance in this metasurface and the localized electromagnetic field enhancement in microfluidic channel are investigated comprehensively. Numerical results show that the calculated quality factor and the corresponding figure of merit can reach 1103 and 244, much higher than previously reported terahertz metamaterials sensors. Moreover, the refractive index sensing capabilities of non-polar and polar liquids are also investigated, which demonstrate the resonant frequency shift does not depend on the losses of analytes and show this device can be used for sensing various materials, including highly absorptive materials. This proposed structure can be extended to work in other frequency regions and has potential applications in high performance gases, liquids and biological materials sensing.
入藏号: WOS:000485742400003
ISSN: 0022-3727
eISSN: 1361-6463
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第 19 条,共 344 条
标题: Wideband and compact TM-pass polarizer based on hybrid plasmonic grating in LNOI
作者: Yu, WQ (Yu, Wenqi); Dai, SX (Dai, Shuangxing); Zhao, QF (Zhao, Qinfeng); Li, JY (Li, Jinye); Liu, JG (Liu, Jianguo)
来源出版物: OPTICS EXPRESS 卷: 27 期: 24 文献号: 378213 DOI: 10.1364/OE.27.034857 出版年: NOV 25 2019
摘要: Based on the transverse electric (TE)/transverse magnetic (TM) polarization diversity in plasmonic Bragg gratings, a compact TM-pass/TE-stop polarizer is theoretically proposed on thin-film lithium niobate on insulator (LNOI) platforms. By introducing a large misalignment between metal gratings on both sides of the LNOI waveguide, we demonstrate a polarizer with a high extinction ratio of 20 dB, a low insertion loss of 2.5 dB, a wide waveband from 1.48 to 1.62 mu m, and a compact size of only 23 mu m on simulation. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000500694800028
PubMed ID: 31878665
ISSN: 1094-4087
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第 20 条,共 344 条
标题: Modified eigenvector-based feature extraction for hyperspectral image classification using limited samples
作者: Wang, WN (Wang, Wenning); Mou, XQ (Mou, Xuanqin); Liu, XB (Liu, Xuebin)
来源出版物: SIGNAL IMAGE AND VIDEO PROCESSING DOI: 10.1007/s11760-019-01604-3 提前访问日期: NOV 2019
摘要: Classical supervised feature extraction methods, such as linear discriminant analysis (LDA) and nonparametric weighted feature extraction (NWFE), and search for projection directions through which the ratio of a between-class scatter matrix to a within-class scatter matrix can be maximized. The two feature extraction methods can obtain good classification results when training samples are sufficient; however, the effect is nonideal when samples are insufficient. In this study, the eigenvector spectra of LDA and NWFE are modified using spectral distribution information, which is locally unstable under the condition of a few samples. Experiments demonstrate that the proposed method outperforms several conventional feature extraction methods.
入藏号: WOS:000498145800001
ISSN: 1863-1703
eISSN: 1863-1711
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第 21 条,共 344 条
标题: Topographic Evolution of Von Karman Crater Revealed by the Lunar Rover Yutu-2
作者: Di, KC (Di, Kaichang); Zhu, MH (Zhu, Meng-Hua); Yue, ZY (Yue, Zongyu); Lin, YT (Lin, Yangting); Wan, WH (Wan, Wenhui); Liu, ZQ (Liu, Zhaoqin); Gou, S (Gou, Sheng); Liu, B (Liu, Bin); Peng, M (Peng, Man); Wang, YX (Wang, Yexin); Niu, SL (Niu, Shengli); Zhang, JH (Zhang, Jinhai); Li, J (Li, Jian); Xie, JF (Xie, Jianfeng); Xi, LH (Xi, Luhua); Yang, JF (Yang, Jianfeng); Xue, B (Xue, Bin)
来源出版物: GEOPHYSICAL RESEARCH LETTERS DOI: 10.1029/2019GL085252 提前访问日期: NOV 2019
摘要: Chang'e-4 (CE-4) achieved the first farside landing in Von Karman crater. In the landing site, linear features have been identified previously from SLDEM and considered to be ejecta from the neighboring Finsen crater. The 5 cm grid spacing digital elevation model of the landing site, generated from the rover's panoramic images, provides more details of the rugged terrain. We further interpret the superimposition of NE-SW ejecta from Finsen crater on the underlying SE-NW dome-like surface relief from Alder crater. The landing site is similar to 70 m higher than the mare basalts within Von Karman crater. Numerical simulations predict similar to 30 and similar to 35 m ejecta deposited at the landing site from Finsen and Alder craters, respectively. The good agreement between the digital elevation model data and ejecta predicted thickness reveals the topographic evolution of Von Karman crater, indicating that the rover-measured material is excavated from Finsen crater with possible contributions from Alder crater.
入藏号: WOS:000497908400001
ISSN: 0094-8276
eISSN: 1944-8007
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第 22 条,共 344 条
标题: Robust contrast-transfer-function phase retrieval via flexible deep learning networks: publisher's note (vol 44, pg 5141, 2019)
作者: Bai, C (Bai, Chen); Zhou, ML (Zhou, Meiling); Min, JW (Min, Junwei); Dang, SP (Dang, Shipei); Yu, XH (Yu, Xianghua); Zhang, P (Zhang, Peng); Peng, T (Peng, Tong); Yao, BL (Yao, Baoli)
来源出版物: OPTICS LETTERS 卷: 44 期: 22 页: 5561-5561 DOI: 10.1364/OL.44.005561 出版年: NOV 15 2019
入藏号: WOS:000496981500044
PubMed ID: 31730108
ISSN: 0146-9592
eISSN: 1539-4794
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第 23 条,共 344 条
标题: Aperture scalable liquid crystal optically duplicated array of phased array
作者: He, XX (He, Xiaoxian); Wang, XR (Wang, Xiangru); Wu, L (Wu, Liang); Liu, XP (Liu, Xiaopeng); Guo, HR (Guo, Hongru); Huang, XN (Huang, Xinning); Xie, XP (Xie, Xiaoping); Tan, QG (Tan, Qinggui); Cao, J (Cao, Jie)
来源出版物: OPTICS COMMUNICATIONS 卷: 451 页: 174-180 DOI: 10.1016/j.optcom.2019.06.037 出版年: NOV 15 2019
摘要: To achieve non-mechanical laser beam steering in the scenario of long distance propagation such as free-space laser communication between satellites, large aperture size is an inevitable issue to be considered to narrow the divergence angle of the output beam. Liquid crystal optical phased array, to be one of the solutions of non-mechanical beam steering, has already shown its obvious potential to achieve a relative large aperture on the order of centimeter. To achieve even larger, its driving matrix becomes squared larger. In this paper, we proposed a novel architecture to realize an optical phased array with a scalable aperture. Meanwhile the driving matrix is almost not increased. It provides the feature of a cascade system with a device of spatial phased modulation and an array of duplicating units. Each unit of the duplicating array is consist of a polarization beam splitter and a half wave plate to have the same output optical field distribution as the input beam whose phase front is modulated by a small size spatial modulator. Not only the property of beam deflection is numerically simulated and experimentally verified, but also the property of divergence angle compression and grating lobes limitation are evaluated. Meanwhile, due to the high precision of the experimental alignment, the non-mechanical beam deflection property is still maintained no matter how many the duplicated unit number is. The relative standard derivation steering error is 0.025.
入藏号: WOS:000480419300028
ISSN: 0030-4018
eISSN: 1873-0310
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第 24 条,共 344 条
标题: Super-resolution imaging reveals changes in Escherichia coli SSB localization in response to DNA damage
作者: Zhao, TY (Zhao, Tianyu); Liu, Y (Liu, Yan); Wang, ZL (Wang, Zilin); He, RY (He, Rongyan); Zhang, JX (Zhang, Jia Xiang); Xu, F (Xu, Feng); Lei, M (Lei, Ming); Deci, MB (Deci, Michael B.); Nguyen, J (Nguyen, Juliane); Bianco, PR (Bianco, Piero R.)
来源出版物: GENES TO CELLS DOI: 10.1111/gtc.12729 提前访问日期: NOV 2019
摘要: The E. coli single-stranded DNA-binding protein (SSB) is essential to viability. It plays key roles in DNA metabolism where it binds to nascent single strands of DNA and to target proteins known as the SSB interactome. There are >2,000 tetramers of SSB per cell with 100-150 associated with the genome at any one time, either at DNA replication forks or at sites of repair. The remaining 1,900 tetramers could constantly diffuse throughout the cytosol or be associated with the inner membrane as observed for other DNA metabolic enzymes. To visualize SSB localization and to ascertain potential spatiotemporal changes in response to DNA damage, SSB-GFP chimeras were visualized using a novel, super-resolution microscope optimized for the study of prokaryotic cells. In the absence of DNA damage, SSB localizes to a small number of foci and the excess protein is associated with the inner membrane where it binds to the major phospholipids. Within five minutes following DNA damage, the vast majority of SSB disengages from the membrane and is found almost exclusively in the cell interior. Here, it is observed in a large number of foci, in discreet structures or, in diffuse form spread over the genome, thereby enabling repair events.
入藏号: WOS:000496241900001
PubMed ID: 31638317
ISSN: 1356-9597
eISSN: 1365-2443
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第 25 条,共 344 条
标题: An efficient framework for unsupervised feature selection
作者: Zhang, H (Zhang, Han); Zhang, R (Zhang, Rui); Nie, FP (Nie, Feiping); Li, XL (Li, Xuelong)
来源出版物: NEUROCOMPUTING 卷: 366 页: 194-207 DOI: 10.1016/j.neucom.2019.07.020 出版年: NOV 13 2019
摘要: In these years, the task of fast unsupervised feature selection attracts much attentions with the increasing number of data collected from the physical world. To speed up the running time of algorithms, the bipartite graph theory has been applied in many large-scale tasks, including fast clustering, fast feature extraction, etc. Inspired by this, we present a novel bipartite graph based fast feature selection approach named Efficient Unsupervised Feature Selection (EUFS). Compared to the existing methods focusing on the same topic, EUFS is advanced in two aspects: (1) we learn a high-quality discrete indicator matrix for these unlabelled data by virtue of bipartite graph based spectral clustering, instead of obtaining an implicit cluster structure matrix; (2) we learn a row-sparse matrix for evaluating features via a generalized uncorrelated regression model supervised by the achieved indicator matrix, which succeeds in exploring the discriminative and uncorrelated features. Correspondingly, the features selected by our model could achieve an excellent clustering or classification performance while maintaining a low computational complexity. Experimentally, the results of EUFS compared to five state-of-the-art algorithms and one baseline on ten benchmark datasets verifies its efficiency and superiority. (C) 2019 Published by Elsevier B.V.
入藏号: WOS:000488202500019
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Nie, Feiping         B-3039-2012         
Zhang, Rui         U-4639-2017         0000-0001-9418-0863
Nie, Feiping                  0000-0002-0871-6519

ISSN: 0925-2312
eISSN: 1872-8286
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第 26 条,共 344 条
标题: A Review of Functional Near-Infrared Spectroscopy Studies of Motor and Cognitive Function in Preterm Infants
作者: Wang, Q (Wang, Quan); Zhu, GP (Zhu, Guang-Pu); Yi, L (Yi, Li); Cui, XX (Cui, Xin-Xin); Wang, H (Wang, Hui); Wei, RY (Wei, Ru-Yi); Hu, BL (Hu, Bing-Liang)
来源出版物: NEUROSCIENCE BULLETIN DOI: 10.1007/s12264-019-00441-1 提前访问日期: NOV 2019
摘要: Preterm infants are vulnerable to brain injuries, and have a greater chance of experiencing neurodevelopmental disorders throughout development. Early screening for motor and cognitive functions is critical to assessing the developmental trajectory in preterm infants, especially those who may have motor or cognitive deficits. The brain imaging technology functional near-infrared spectroscopy (fNIRS) is a portable and low-cost method of assessing cerebral hemodynamics, making it suitable for large-scale use even in remote and underdeveloped areas. In this article, we review peer-reviewed, scientific fNIRS studies of motor performance, speech perception, and facial recognition in preterm infants. fNIRS provides a link between hemodynamic activity and the development of brain functions in preterm infants. Research using fNIRS has shown different patterns of hemoglobin change during some behavioral tasks in early infancy. fNIRS helps to promote our understanding of the developmental mechanisms of brain function in preterm infants when performing motor or cognitive tasks in a less-restricted environment.
入藏号: WOS:000495946000001
PubMed ID: 31713716
ISSN: 1673-7067
eISSN: 1995-8218
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第 27 条,共 344 条
标题: Tripartite Einstein-Podolsky-Rosen steering with linear and nonlinear beamsplitters in four-wave mixing of Rubidium atoms
作者: Liu, Y (Liu, Yang); Cai, Y (Cai, Yin); Xiang, Y (Xiang, Yu); Li, F (Li, Feng); Zhang, YP (Zhang, Yanpeng); He, QY (He, Qiongyi)
来源出版物: OPTICS EXPRESS 卷: 27 期: 23 页: 33070-33079 DOI: 10.1364/OE.27.033070 出版年: NOV 11 2019
摘要: Multipartite Einstein-Podolsky-Rosen (EPR) steering is an essential resource for secure one-sided device-independent quantum secret sharing. Here, we analyze the EPR steering properties exhibited in three-mode Gaussian states created by four-wave mixing (FWM) in Rubidium atoms combined with a linear beamsplitter and a nonlinear beamsplitter (second FWM), respectively. By quantifying Gaussian steerability based on a measure determined by the covariance matrix of the produced states, we compare the performance of two schemes to achieve one-way, collective, and genuine tripartite steering, as well as the monogamy constraints for distributing steering among three parties. We show that the scheme with nonlinear beamsplitter is feasible to create stronger bipartite steering and genuine tripartite steering and has more flexibility to manipulate the monogamy relation through the cooperation of the two cascaded FWM processes. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000495871300019
PubMed ID: 31878381
ISSN: 1094-4087
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第 28 条,共 344 条
标题: Toward high contrast and high-resolution microscopic ghost imaging
作者: Sun, Z (Sun, Zhe); Tuitje, F (Tuitje, Frederik); Spielmann, C (Spielmann, Christian)
来源出版物: OPTICS EXPRESS 卷: 27 期: 23 页: 33653-33662 DOI: 10.1364/OE.27.033652 出版年: NOV 11 2019
摘要: In this study, the influence of speckle size on contrast-to-noise ratio (CNR) and resolution is examined based on the object dimensions in the macroscopic and microscopic regimes. This research shows that for microscopic samples the conventional scaling laws are no longer effective and the CNR does not counter-propagate in the same manner as the resolution. To our knowledge, a deviation in CNR scaling on speckle size is observed for the first time in the field of microscopic ghost imaging. This result was verified using two different sample shapes. In addition, numerical analysis revealed that the noise of the photodiode is a limiting factor for the CNR. Based on these findings, the conditions for identifying the parameter set that maximizes the CNR and provides high resolution images was defined, which achieving high-quality microscopic ghost images. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000495871300066
PubMed ID: 31878428
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Spielmann, Christian         G-9476-2013         0000-0002-5223-4170

ISSN: 1094-4087
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第 29 条,共 344 条
标题: Disentangling the Luminescent Mechanism of Cs4PbBr6 Single Crystals from an Ultrafast Dynamics Perspective
作者: Liu, RT (Liu, Rui-Tong); Zhai, XP (Zhai, Xin-Ping); Zhu, ZY (Zhu, Zhi-Yuan); Sun, B (Sun, Bing); Liu, DW (Liu, Duan-Wu); Ma, B (Ma, Bo); Zhang, ZQ (Zhang, Ze-Qi); Sun, CL (Sun, Chun-Lin); Zhu, BL (Zhu, Bing-Li); Zhang, XD (Zhang, Xiao-Dong); Wang, Q (Wang, Qiang); Zhang, HL (Zhang, Hao-Li)
来源出版物: JOURNAL OF PHYSICAL CHEMISTRY LETTERS 卷: 10 期: 21 页: 6572-6577 DOI: 10.1021/acs.jpclett.9b02590 出版年: NOV 7 2019
摘要: New all-inorganic perovskites like Cs4PbBr6 provide rich luminescent tools and particularly novel physical insights, including their zero-dimensional structure and controversial emitting mechanism. The ensuing debate over the origin of the luminescence of Cs4PbBr6 inspired us to tackle the issue through fabricating high-quality Cs4PbBr6 single crystals and employing ultrafast dynamics study. Upon photoexcitation, Cs4PbBr6 underwent dynamics steps distinct from that of CsPbBr3, including exciton migration to the defect level on a time scale of several hundred femtoseconds, exciton relaxation within the defect states on the picosecond time scale, and exciton recombination from the subnanosecond to nanosecond time scale. The observation disclosed that crystal defects of Cs4PbBr6 induced green emission while CsPbBr3 mainly relied on quantum confinement to emit at room temperature. The study provides an in-depth understanding of the photoinduced multistep dynamics steps of Cs4PbBr6 associated with display and photovoltaic applications, establishing Cs4PbBr6 as a new candidate for uses associated with the perovskite family of materials.
入藏号: WOS:000495805100021
PubMed ID: 31594309
ISSN: 1948-7185
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第 30 条,共 344 条
标题: Phase control and stabilization in attosecond beamline with fast Fourier transform
作者: Jiang, YJ (Jiang Yu-Jiao); Gao, YT (Gao Yi-Tan); Huang, P (Huang Pei); Zhao, K (Zhao Kun); Xu, SY (Xu Si-Yuan); Zhu, JF (Zhu Jiang-Feng); Fang, SB (Fang Shao-Bo); Teng, H (Teng Hao); Hou, X (Hou Xun); Wei, ZY (Wei Zhi-Yi)
来源出版物: ACTA PHYSICA SINICA 卷: 68 期: 21 文献号: 214204 DOI: 10.7498/aps.68.20191164 出版年: NOV 5 2019
摘要: With the unveiling of molecular and atomic dynamics, scientists crave finer and faster tools to communicate with the microworld. Attosecond pump-probe enjoys its reputation as the fastest camera, hinting ultrafast movements in the delay graph. To employ this camera, the stability and delay control should have very great accuracy comparable to the camera resolution. It is also of significant importance for stabilizing the carrier envelope phase (CEP) in few-cycle laser field. When dealing with a huge quantity of data, conventional Fourier transform algorism is challenging in high-speed control. Here we put forward the efficient calculation method, fast Fourier transform (FFT) algorism in Mach-Zehnder interferometer for arm length locking and f-2f for CEP locking. In the interferometer locking, 532 nm continuous wave laser is used in the Mach-Zehnder interferometer, and the phase of the FFT term corresponding to the delay between the two arms of the interferometer serves as a feedback signal on piezo transducer (PZT) in the delay line to reduce the change of the arm length. In the CEP control experiment, data to be analyzed are the f-2f spectrum interference fringes recorded by the spectrometer. The CEP values are obtained from the first order of FFT module output of the integrated spectrum interference fringes, and a labview program examines the relative phase drift and sends a feedback voltage signal to the PZT through the proportion integration differentiation module to compensate slow CEP drift after the chirped pulse amplification system by changing the insert length of a prism pair. The results show that the root mean square (RMS) of the arm length difference is 1.24 nm (4.1 attosecond for light to travel) per meter in the interferometer locking over 12 h, and the RMS of CEP is 227 mrad under 3 ms integration time in the CEP locking over 20 min. These results are able to meet the requirement of the accuracy for attosecond pulse generation and attosecond pump-probe experiments. We also use FFT to stabilize the CEP and relative time simultaneously in the waveform synthesis for 8 h (Huang P, Fang S, Gao Y, Zhao K, Hou X, Wei Z 2019 Appl. Phys. Lett. 115 031102), the phase-locking system results in a CEP stability of 280 mrad and a relative time stability of 110 as at a repetition rate of 1 kHz. These results imply that the FFT is versatile and reliable in ultrafast control.
入藏号: WOS:000496172100009
ISSN: 1000-3290
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第 31 条,共 344 条
标题: White-Light Image Reconstruction via Seeded Modulation Instability
作者: Zhang, YB (Zhang, Yongbin); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu)
来源出版物: PHYSICAL REVIEW APPLIED 卷: 12 期: 5 文献号: 054005 DOI: 10.1103/PhysRevApplied.12.054005 出版年: NOV 4 2019
摘要: Nonlinear imaging preserves more detailed information by exploiting the presence and interaction of many photons in nonlinear optics. Despite significant progress, nonlinear methods for white-light image recovery are still lacking. We report the white-light image reconstruction via seeded modulation instability, which is called dynamical stochastic resonance. The underlying signals are illuminated with white light emitted from a light-emitting diode and are reinforced by coupling with scattering noise in a noninstantaneous self-focusing medium. Our experimental results show that this nonlinear approach is effective in improving the contrast and visibility of completely blurred white-light images by guiding noise rather than by filtering noise. The signals of the entire temporal spectrum collectively seed a potential in the medium. In turn, the potential leads to the enhancement of signal modes by concentrating scattering noise. A theoretical growth rate is derived and the numerical simulations are presented to match the experimental observation. We also demonstrate that the underlying signals can be preferably reproduced by asynchronously probing the seeded potential with another white-light beam. Our work reveals an alternative scheme for white-light image detection.
入藏号: WOS:000494035000002
ISSN: 2331-7019
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第 32 条,共 344 条
标题: A Systematic Error Compensation Method Based on an Optimized Extreme Learning Machine for Star Sensor Image Centroid Estimation
作者: Wei, X (Wei, Xin); Wen, DS (Wen, Desheng); Song, ZX (Song, Zongxi); Xi, JB (Xi, Jiangbo); Zhang, WK (Zhang, Weikang); Liu, G (Liu, Gang); Li, ZX (Li, Zhixin)
来源出版物: APPLIED SCIENCES-BASEL 卷: 9 期: 22 文献号: 4751 DOI: 10.3390/app9224751 出版年: NOV 2 2019
摘要: As an important error in star centroid location estimation, the systematic error greatly restricts the accuracy of the three-axis attitude supplied by a star sensor. In this paper, an analytical study about the behavior of the systematic error in the center of mass (CoM) centroid estimation method under different Gaussian widths of starlight energy distribution is presented by means of frequency field analysis and numerical simulations. Subsequently, an optimized extreme learning machine (ELM) based on the bat algorithm (BA) is adopted to predict the systematic error of the actual star centroid position and then compensate the systematic error from the CoM method. In the BA-ELM model, the input weights matrix and hidden layer biases parameters are encoded as microbat's locations and optimized by utilizing the strong global search capacity of BA, which significantly improves the performance of ELM in terms of prediction accuracy. The simulation result indicates that our method can reduce the systematic error to less than 3.0 x 10(-7) pixels, and its compensation accuracy is two or three orders of magnitude higher than that of other methods for estimating a star centroid location under a 3 x 3 pixel sampling window.
入藏号: WOS:000502570800028
eISSN: 2076-3417
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第 33 条,共 344 条
标题: The Radiative Transfer Characteristics of the O-2 Infrared Atmospheric Band in Limb-Viewing Geometry
作者: He, WW (He, Weiwei); Wu, KJ (Wu, Kuijun); Feng, YT (Feng, Yutao); Fu, D (Fu, Di); Chen, ZW (Chen, Zhenwei); Li, FQ (Li, Faquan)
来源出版物: REMOTE SENSING 卷: 11 期: 22 文献号: 2702 DOI: 10.3390/rs11222702 出版年: NOV 2 2019
摘要: The O-2(a(1)Delta(g)) emission near 1.27 mu m provides an important means to remotely sense the thermal characteristics, dynamical features, and compositional structures of the upper atmosphere because of its photochemistry and spectroscopic properties. In this work, an emission-absorption transfer model for limb measurements was developed to calculate the radiation and scattering spectral brightness by means of a line-by-line approach. The nonlocal thermal equilibrium (non-LTE) model was taken into account for accurate calculation of the O-2(a(1)Delta(g)) emission by incorporating the latest rate constants and spectral parameters. The spherical adding and doubling methods were used in the multiple scattering model. Representative emission and absorption line shapes of the O-2(a(1)Delta(g), upsilon ' = 0) -> O-2(X-3 Sigma(g), upsilon '' = 0) band and their spectral behavior varying with altitude were examined. The effects of solar zenith angle, surface albedo, and aerosol loading on the line shapes were also studied. This paper emphasizes the advantage of using infrared atmospheric band for remote sensing of the atmosphere from 20 up to 120 km, a significant region where the strongest coupling between the lower and upper atmosphere occurs.
入藏号: WOS:000502284300107
eISSN: 2072-4292
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第 34 条,共 344 条
标题: Security analysis of continuous-variable quantum key distribution with imperfect Faraday mirror
作者: Liang, KX (Liang, Kexin); Cao, ZW (Cao, Zhengwen); Liu, WQ (Liu, Weiqi); Wang, JY (Wang, Jiayao); Chai, G (Chai, Geng); Zhang, TY (Zhang, Tongyi)
来源出版物: LASER PHYSICS LETTERS 卷: 16 期: 11 文献号: 115202 DOI: 10.1088/1612-202X/ab4995 出版年: NOV 2019
摘要: For the practical Faraday mirror ( FM) in a continuous-variable quantum key distribution (CVQKD) system there exists a rotation angle deviation that can lead to a loss of photon number when a light message passes through the polarization beam splitter. Here we employ the entanglement-based model to research the influence of the FM's imperfection. Based on parameter estimation, the imperfection can introduce a loophole for Eve to obtain information. The secret key rate of the CVQKD will be impaired. Finally, a novel method is proposed to ensure system performance by compensating optical power, and we further study the relationship between the secret key rate and the modulation variance.
入藏号: WOS:000503753800002
ISSN: 1612-2011
eISSN: 1612-202X
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第 35 条,共 344 条
标题: Microtapered long period gratings: Non-destructive fabrication, highly sensitive torsion sensing, and tunable broadband filtering
作者: Liu, JH (Liu, Jihong); Cheng, MH (Cheng, Minhui); Kong, XD (Kong, Xudong); Han, DD (Han, Dongdong); Dong, J (Dong, Jun); Luo, WF (Luo, Wenfeng); Ren, KL (Ren, Kaili)
来源出版物: INFRARED PHYSICS & TECHNOLOGY 卷: 102 文献号: UNSP 103000 DOI: 10.1016/j.infrared.2019.103000 出版年: NOV 2019
摘要: A promising technology for non-destructive fabricating microtapered long period fiber gratings (MT-LPFGs) is demonstrated by periodically slight tapering single-mode fiber. Owing to the optimized microtapering technique, high-quality LPFGs with dip attenuations of about 40 dB, insertion loss < 0.5 dB are easily fabricated by precisely controlling the slightly tapering process. In addition, based on the characteristics of the MT-LPFG, not only highly strain, bending and torsion sensing are investigated experimentally, but also all-fiber broadband and extremely deep (- 70 dB) band-rejection filters are proposed and demonstrated. The performances of the sensors and filters are significantly improved several times compared with conventional technology.
入藏号: WOS:000498748400022
ISSN: 1350-4495
eISSN: 1879-0275
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第 36 条,共 344 条
标题: A chirped fiber Bragg grating with triple functions for stable wavelength-tunable Yb-doped fiber laser
作者: Yang, HR (Yang, Huiran); Li, WL (Li, Wenlei); Chen, GW (Chen, Guangwei)
来源出版物: INFRARED PHYSICS & TECHNOLOGY 卷: 102 文献号: UNSP 103008 DOI: 10.1016/j.infrared.2019.103008 出版年: NOV 2019
摘要: Chirped fiber Bragg gratings (CFBGs) have been extensively employed as dispersion compensation element in mode-locked fiber lasers. However, multiple functions of CFBG in fiber lasers have not been studied adequately. Here, triple functions of CFBG, dispersion compensation, distributed reflection performance, and stabilizing mode-locked operation, are experimentally investigated. Firstly, the generation of dissipative solitons (DSs) in an all-normal-dispersion Yb-doped fiber laser is reported, while the mode-locked operation is proved to be insufficiently stable. In order to improve performance of the laser, a conventional solitons (CSs) fiber laser is obtained by inserting a CFBG with large anomalous dispersion into the laser cavity. Besides, the distributed reflection performance of CFBG is researched and a wavelength-tunable fiber laser with tuning range of center wavelength from 1033.5 to 1035.5 ran is achieved. It is no doubt that our work opens up venues to create wavelength tunable Yb-doped fiber laser systems with extremely high stability.
入藏号: WOS:000498748400032
ISSN: 1350-4495
eISSN: 1879-0275
________________________________________
第 37 条,共 344 条
标题: Infrared and visible image fusion algorithm based on saliency detection and adaptive double-channel spiking cortical model
作者: Zhao, C (Zhao, Cheng); Huang, YD (Huang, Yongdong); Qiu, S (Qiu, Shi)
来源出版物: INFRARED PHYSICS & TECHNOLOGY 卷: 102 文献号: UNSP 102976 DOI: 10.1016/j.infrared.2019.102976 出版年: NOV 2019
摘要: Based on the saliency detection which effectively extracts the saliency information of the image and the adaptive double-channel spiking cortical model (ADSCM) which has the advantages of global coupling, pulse synchronization, less parameters and high computational efficiency, which can well process information in dark areas, we proposed a new infrared and visible image fusion algorithm. Firstly, the infrared and visible images are decomposed into the base layer and the detail layers through the rolling guidance filter (RGF). Secondly, the base layer is fused with an improved saliency detection method, and the detail layers are fused by a directional gradient sum and an improved ADSCM. The experimental results show that the proposed method can also fully extract the target information of the infrared image while preserving the visible background information, in which the fusion effect is better than the traditional fusion algorithms.
入藏号: WOS:000498748400002
ISSN: 1350-4495
eISSN: 1879-0275
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第 38 条,共 344 条
标题: Tunable Fiber Laser Using an ErYb Codoped Fiber Based Modal Interferometer Filter
作者: Yang, HN (Yang, Hening); Dong, B (Dong, Bo); Zhao, W (Zhao, Wei); Chen, EQ (Chen, Enqing); Li, Y (Li, Yang); Si, JH (Si, Jinhai)
来源出版物: JOURNAL OF LIGHTWAVE TECHNOLOGY 卷: 37 期: 21 页: 5555-5560 DOI: 10.1109/JLT.2019.2933703 出版年: NOV 1 2019
摘要: A tunable erbium-doped fiber laser (EDFL) is proposed and demonstrated experimentally. It is based on a tunable fiber filter using the pump induced refractive index change characteristics of the ErYb codoped phosphosilicate fiber (EYDF) based modal interferometer (MI). The laser achieves a tunability of 2.39nm and 1.60nm, with the wavelength linearly tuned from 1534.05nm to 1536.44nm and from 1554.36nm to 1555.96nm by changing the pump power injected into the MI. Its side mode suppression ratios are 30dB and 33dB, respectively. The stability of the tunable EDFL is getting better with the continuous improvement of the power of pump 1, and the dual-wavelength power fluctuations are less than 0.22dB and 0.12dB within 20 min at 250mW of pump 1, respectively.
入藏号: WOS:000495677100025
ISSN: 0733-8724
eISSN: 1558-2213
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第 39 条,共 344 条
标题: X-ray transmittance characteristics and potential communication in re-enter plasma sheath
作者: Li, Y (Li, Yao); Su, T (Su, Tong); Sheng, LZ (Sheng, Lizhi); Qiang, PF (Qiang, Pengfei); Xu, N (Xu, Neng); Zhao, BS (Zhao, Baosheng)
来源出版物: OPTIK 卷: 197 文献号: UNSP 162917 DOI: 10.1016/j.ijleo.2019.06.017 出版年: NOV 2019
摘要: X-ray communication has a broad application prospect since it was introduced by NASA in 2007. Combination with modern digital X-ray source, X-ray communication shows a promising prospect in the further spatial communication, especially on harsh condition. In this paper, to begin with, transmission co-efficiency of X-ray signal penetrate in plasma sheath were analysised theoretically and experimentally. Simulation results indicate that X-ray signal was not influenced by the re-enter plasma sheath. Then a glow discharge plasma source was used to analysis the transmission characteristics. When the plasma electron density ranges from 6 x 10(16)/m(3) to 1.2 x 10(16)/m(3), the thickness of plasma medium is 18 cm, transmission co-efficiency of X-ray signal increases with the rise of photon energy and flux. For example, a 2.4Mcps X-ray flux with 20 kV anode voltage can achieve more than 95% transmission co-efficiency. Finally, a Monte Carlo simulation was used to analysis the feasibility of X-ray communication in re-enter condition, which indicates 1.3Mbps transmitting speed could be achieved in the re-enter condition theoretically. These results pointed out that X-ray communication can mitigate the effects of plasma sheath and open a novel way to solve this problem.
入藏号: WOS:000494479400001
ISSN: 0030-4026
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第 40 条,共 344 条
标题: Magnetic properties and photoluminescence of thulium-doped calcium aluminosilicate glasses
作者: So, B (So, Byoungjin); She, JB (She, Jiangbo); Ding, YC (Ding, Yicong); Miyake, J (Miyake, Jinsuke); Atsumi, T (Atsumi, Taisuke); Tanaka, K (Tanaka, Katsuhisa); Wondraczek, L (Wondraczek, Lothar)
来源出版物: OPTICAL MATERIALS EXPRESS 卷: 9 期: 11 页: 4348-4359 DOI: 10.1364/OME.9.004348 出版年: NOV 1 2019
摘要: We report on the optical and magnetic properties of Tm2O3-doped calcium aluminosilicate glasses with dopant concentrations of up to 7 mol%. These materials provide a rare case in which high magnetic susceptibility, low Faraday rotation, Tm3+-related infrared photoluminescence and the ability to produce optical fibers are combined. From emission intensity and decay curves of the H-3(4)-> F-3(4) and (3)F4 -> H-3(6) transitions, we find cross-relaxation already for 0.5 mol% of Tm2O3 doping, indicating notable Tm2O3 clustering. This facilitates antiferromagnetic interaction and results in high magnetic susceptibility. Substitution of Al2O3 by Tm2O3 induces a more asymmetric local structural environment around Tm3+ species and enhances the diamagnetic contribution to Faraday rotation as opposed to the other rare-earth ions. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000493994700021
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wondraczek, Lothar                  0000-0002-0747-3076

ISSN: 2159-3930
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第 41 条,共 344 条
标题: Robust contrast-transfer-function phase retrieval via flexible deep learning networks
作者: Bai, C (Bai, Chen); Zhou, ML (Zhou, Meiling); Min, JW (Min, Junwei); Dang, SP (Dang, Shipei); Yu, XH (Yu, Xianghua); Zhang, P (Zhang, Peng); Peng, T (Peng, Tong); Yao, BL (Yao, Baoli)
来源出版物: OPTICS LETTERS 卷: 44 期: 21 页: 5141-5144 DOI: 10.1364/OL.44.005141 出版年: NOV 1 2019
摘要: By exploiting the total variation (TV) regularization scheme and the contrast transfer function (CTF), a phase map can be retrieved from single-distance coherent diffraction images via the sparsity of the investigated object. However, the CTF-TV phase retrieval algorithm often struggles in the presence of strong noise, since it is based on the traditional compressive sensing optimization problem. Here, convolutional neural networks, a powerful tool from machine learning, are used to regularize the CTF-based phase retrieval problems and improve the recovery performance. This proposed method, the CTF-Deep phase retrieval algorithm, was tested both via simulations and experiments. The results show that it is robust to noise and fast enough for high-resolution applications, such as in optical, x-ray, or terahertz imaging. (C) 2019 Optical Society of America
入藏号: WOS:000493940500010
PubMed ID: 31674951
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yu, Xianghua                  0000-0002-7447-1396

ISSN: 0146-9592
eISSN: 1539-4794
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第 42 条,共 344 条
标题: Optofluidic in-fiber integrated surface-enhanced Raman spectroscopy detection based on a hollow optical fiber with a suspended core
作者: Gao, DH (Gao, Danheng); Yang, XH (Yang, Xinghua); Teng, PP (Teng, Pingping); Liu, ZH (Liu, Zhihai); Yang, J (Yang, Jun); Kong, DP (Kong, Depeng); Zhang, JZ (Zhang, Jianzhong); Luo, M (Luo, Meng); Li, ZN (Li, Zhanao); Tian, FJ (Tian, Fengjun); Yuan, LB (Yuan, Libo)
来源出版物: OPTICS LETTERS 卷: 44 期: 21 页: 5173-5176 DOI: 10.1364/OL.44.005173 出版年: NOV 1 2019
摘要: In this Letter, we propose, to the best of our knowledge, the first in-fiber optofluidic Raman surface-enhanced Raman spectroscopy (SERS) sensor based on a microstructured hollow fiber (MHF) with a suspended core. Taking advantage of the unique internal structure, we immobilize silver nanoparticles with an SERS effect in the MHF by chemical bonding. The Raman signal of the microfluidic sample is excited by the excitation light in the suspended core through an evanescent field. Then the online SERS signal can be coupled back into the core and detected. To demonstrate the feasibility of the device, rhodamine 6G is chosen as the analyte, and high-quality SERS spectra are detected with the limit of detection of 1 x 10(-14) M. Furthermore, an online optofluidic test is conducted on ceftriaxone (C18H18N8O7S3) to examine its capabilities in antibiotic sensing. The results show that the LOD of the samples is 10(-6) M. Significantly, this Letter provides an integrated optofluidic in-fiber SERS sensor with a microchannel that can be integrated with chip devices without spatial optical coupling, which has a broad application in medicine and food safety, as well as various aspects of biological in-fiber sensing. (C) 2019 Optical Society of America
入藏号: WOS:000493940500018
PubMed ID: 31674959
ISSN: 0146-9592
eISSN: 1539-4794
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第 43 条,共 344 条
标题: High birefringence, low loss, and flattened dispersion photonic crystal fiber for terahertz application
作者: Wang, DD (Wang, Dou-Dou); Mu, CL (Mu, Chang-Long); Kong, DP (Kong, De-Peng); Guo, CY (Guo, Chen-Yu)
来源出版物: CHINESE PHYSICS B 卷: 28 期: 11 文献号: 118701 DOI: 10.1088/1674-1056/ab44af 出版年: NOV 2019
摘要: A type of photonic crystal fiber based on Kagome lattice cladding and slot air holes in a rectangular core is investigated. Full vector finite element method is used to evaluate the modal and propagation properties of the designed fiber. High birefringence of 0.089 and low effective material loss of 0.055 cm(?1) are obtained at 1 THz. The y-polarized fundamental mode of the designed fiber shows a flattened and near-zero dispersion of 0 & xfffd; 0.45 ps & xfffd; THz(?1) & xfffd; cm(?1) within a broad frequency range (0.5 THz?1.5 THz). Our results provide the theory basis for applications of the designed fiber in terahertz polarization maintaining systems.
入藏号: WOS:000493082100001
ISSN: 1674-1056
eISSN: 1741-4199
________________________________________
第 44 条,共 344 条
标题: Suspended graded-index porous core POF for ultra-flat near-zero dispersion terahertz transmission
作者: Mei, S (Mei, Sen); Kong, DP (Kong, Depeng); Wang, LL (Wang, Lili); Ma, T (Ma, Tian); Zhu, YF (Zhu, Yuanfeng); Zhang, XD (Zhang, Xiaodong); He, ZQ (He, Zhengquan); Huang, XS (Huang, Xiangsheng); Zhang, YN (Zhang, Yani)
来源出版物: OPTICAL FIBER TECHNOLOGY 卷: 52 文献号: 101946 DOI: 10.1016/j.yofte.2019.101946 出版年: NOV 2019
摘要: A suspended graded-index porous core polymer optical fiber (POF) for low-dispersion terahertz guidance is proposed. This fiber is consisting of a graded-index porous core, five spoke-like dielectric supporting strips and an outer material ring. The finite element method (FEM) with perfectly matched layer boundary conditions is used to simulate the guiding properties. It is found that by creating artificial graded-index in the porous core, an extremely flat group velocity dispersion (GVD) of 0.14 +/- 0.07 ps/(THz.cm) is achieved in the range of 0.71-0.95 THz when fiber core diameter is 432 mu m and the air porosity is 44%. Meanwhile, the fiber shows low and flat intermodal dispersion of 0.0152 +/- 0.0004 ps/(THz.cm) at 0.8-1 THz under the same conditions. Moreover, other optical parameters of the fiber such as confinement loss (CL), effective material loss (EML) and normalized frequency V are also investigated.
入藏号: WOS:000491237100048
ISSN: 1068-5200
eISSN: 1095-9912
________________________________________
第 45 条,共 344 条
标题: Design and magneto-optical characteristics of Ge-Sb-S-PbI2 chalcogenide glasses with a high Verdet constant
作者: Xu, YT (Xu, Yantao); Guo, HT (Guo, Haitao); Liu, XG (Liu, Xiaogang); Cui, J (Cui, Jian); Xiao, XS (Xiao, Xusheng); Cui, XX (Cui, Xiaoxia); Guo, JJ (Guo, Junjiang); She, JB (She, Jiangbo); Lu, M (Lu, Min); Peng, B (Peng, Bo)
来源出版物: JOURNAL OF THE AMERICAN CERAMIC SOCIETY 卷: 102 期: 11 页: 6787-6793 DOI: 10.1111/jace.16551 出版年: NOV 2019
摘要: To develop high-performance magneto-optical chalcogenide glasses and clarify the mechanisms of the Verdet constant, a series of GeS2-Sb2S3-PbI2 chalcogenide glasses were designed and fabricated, and their Faraday effects were investigated at a wavelength of 980 nm. A new parameter, that is, average polarizability, was proposed, and the results show that the Verdet constant has a good linear relationship with average polarizability, meaning that the Verdet constant of a chalcogenide glass can be directly estimated by its chemical constituents. The Verdet constant is as large as 0.200 min G(-1) cm(-1) at 980 nm for 22.5GeS(2)-67.5Sb(2)S(3)-10PbI(2) composition glass, which is the largest value reported thus far for sulfide glasses; this glass also possesses good thermal and optical properties and therefore might be an attractive candidate for mid-infrared magneto-optical device applications.
入藏号: WOS:000484534300043
ISSN: 0002-7820
eISSN: 1551-2916
________________________________________
第 46 条,共 344 条
标题: Effect of glass composition on the physical properties and luminescence of Pr3+ ion-doped chalcogenide glasses
作者: Ma, CC (Ma, Chengcheng); Guo, HT (Guo, Haitao); Xu, YS (Xu, Yinsheng); Wu, ZH (Wu, Zhihao); Li, MM (Li, Mingming); Jia, XM (Jia, Xiaomeng); Nie, QH (Nie, Qiuhua)
来源出版物: JOURNAL OF THE AMERICAN CERAMIC SOCIETY 卷: 102 期: 11 页: 6794-6801 DOI: 10.1111/jace.16592 出版年: NOV 2019
摘要: In this work, Pr3+ ion-doped Ge20Ga15-xSbxSe65 (x = 0, 5, 10, in mol%), Ge20Sb15-yInySe65 (y = 5, 10, in mol%), Ge20Ga15-zInzSe65 (z = 0, 5, 10, in mol%), and Ge20Ga5Sb10Se60I5 glasses were prepared. The structural units, thermal properties, and optical properties of these glasses were analyzed. In addition, a comprehensive comparison study of the effects of metal ions (Sb, Ga, and In), S/Se ratio, and I content on the mid-infrared (MIR) luminescence of Pr3+ ions was conducted. Under a 1.55-mu m laser pump, 0.2 mol% of Pr3+ ion-doped chalcogenide glasses performed strong photoluminescence in the wavelength range of 3.5-5.5 mu m. Results indicated that the Sb-containing glass performed the strongest emission intensity among the studied glasses. Moreover, halogen element I can reduce the phonon energy of the matrix, which is beneficial to the luminescence of Pr3+ ions and provide significant possibilities for developing MIR lasers and amplifiers.
入藏号: WOS:000484534300044
ISSN: 0002-7820
eISSN: 1551-2916
________________________________________
第 47 条,共 344 条
标题: CAM-RNN: Co-Attention Model Based RNN for Video Captioning
作者: Zhao, B (Zhao, Bin); Li, XL (Li, Xuelong); Lu, XQ (Lu, Xiaoqiang)
来源出版物: IEEE TRANSACTIONS ON IMAGE PROCESSING 卷: 28 期: 11 DOI: 10.1109/TIP.2019.2916757 出版年: NOV 2019
摘要: Video captioning is a technique that bridges vision and language together, for which both visual information and text information are quite important. Typical approaches are based on the recurrent neural network (RNN), where the video caption is generated word by word, and the current word is predicted based on the visual content and previously generated words. However, in the prediction of the current word, there is much uncorrelated visual content, and some of the previously generated words provide little information, which may cause interference in generating a correct caption. Based on this point, we attempt to exploit the visual and text features that are most correlated with the caption. In this paper, a co-attention model based recurrent neural network (CAM-RNN) is proposed, where the CAM is utilized to encode the visual and text features, and the RNN works as the decoder to generate the video caption. Specifically, the CAM is composed of a visual attention module, a text attention module, and a balancing gate. During the generation procedure, the visual attention module is able to adaptively attend to the salient regions in each frame and the frames most correlated with the caption. The text attention module can automatically focus on the most relevant previously generated words or phrases. Moreover, between the two attention modules, a balancing gate is designed to regulate the influence of visual features and text features when generating the caption. In practice, the extensive experiments are conducted on four popular datasets, including MSVD, Charades, MSR-VTT, and MPII-MD, which have demonstrated the effectiveness of the proposed approach.
入藏号: WOS:000484209100003
PubMed ID: 31107650
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 1057-7149
eISSN: 1941-0042
________________________________________
第 48 条,共 344 条
标题: Observation of dissipative soliton bound states in a nonlinear multimodal interference based all-fiber all-normal-dispersion mode-locking laser
作者: Lv, ZG (Lv, Zhiguo); Yang, Z (Yang, Zhi); Song, DD (Song, DongDong); Li, F (Li, Feng); Yang, Y (Yang, Yang); Yang, XJ (Yang, Xiaojun); Wang, YS (Wang, Yishan); Li, QL (Li, Qianglong); Zhao, W (Zhao, Wei)
来源出版物: OPTICS AND LASER TECHNOLOGY 卷: 119 文献号: 105626 DOI: 10.1016/j.optlastec.2019.105626 出版年: NOV 2019
摘要: This work, for the first time, demonstrates the generation of the bound soliton states in a nonlinear multimodal interference (NL-MMI) based ytterbium-doped all-normal-dispersion dissipative soliton mode-locking laser. Further, up to the third harmonic mode-locked bound soliton states with rotating phase difference can be generated under the appropriate optimization of the laser cavity parameters. Furthermore, the evolution dynamics and compressibility of the harmonic mode-locked bound soliton states have also been respectively investigated in order to reveal the temporal distribution characteristics of the highly chirped bound soliton states and inter-pulse separation after dispersion compensation.
入藏号: WOS:000482244400054
ISSN: 0030-3992
eISSN: 1879-2545
________________________________________
第 49 条,共 344 条
标题: Weather recognition via classification labels and weather-cue maps
作者: Zhao, B (Zhao, Bin); Hua, LL (Hua, Lulu); Li, XL (Li, Xuelong); Lu, XQ (Lu, Xiaoqiang); Wang, ZG (Wang, Zhigang)
来源出版物: PATTERN RECOGNITION 卷: 95 页: 272-284 DOI: 10.1016/j.patcog.2019.06.017 出版年: NOV 2019
摘要: Although it is of great importance to recognize weather conditions automatically, this task has not been explored thoroughly in practice. Generally, most approaches in the literature simply treat it as a common image classification task, i.e., assigning a certain weather label to each image. However, there are significant differences between weather recognition and common image classification, since several weather conditions tend to occur simultaneously, like foggy and cloudy. Obviously, a single weather label is insufficient to provide a comprehensive description of the weather conditions. In this case, we propose to utilize auxiliary weather-cues, e.g., black clouds and blue sky, for comprehensive weather description. Specifically, a multi-task framework is designed to jointly deal with the weather-cue segmentation task and weather classification task. Benefit from the intrinsic relationships lying in the two tasks, exploring the information of weather-cues can not only provide a comprehensive description of weather conditions, but also help the weather classification task to learn more effective features, and further improve the performance. Besides, we construct two large-scale weather recognition datasets equipped with both weather labels and segmentation masks of weather-cues. Experiment results demonstrate the excellent performance of our approach. The constructed two datasets will be available at https://github.com/wzgwzg/Multitask_Weather. (C) 2019 Elsevier Ltd. All rights reserved.
入藏号: WOS:000478710600023
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0031-3203
eISSN: 1873-5142
________________________________________
第 50 条,共 344 条
标题: Direct calculation of tightly focused field in an arbitrary plane
作者: Cai, YA (Cai, Yanan); Wang, ZJ (Wang, Zhaojun); Liang, YS (Liang, Yansheng); Ren, FF (Ren, Feifei); Yao, BL (Yao, Baoli); Lei, M (Lei, Ming); Yan, SH (Yan, Shaohui)
来源出版物: OPTICS COMMUNICATIONS 卷: 450 页: 329-334 DOI: 10.1016/j.optcom.2019.06.022 出版年: NOV 1 2019
摘要: The Debye-Wolf diffraction integral is a powerful tool for computing the focused field of an illumination by a high numerical aperture (NA) objective lens. With the help of the fast Fourier Transform (FT) algorithm, this integral can be evaluated at a high processing speed. In general, the FT pair is the illumination field at the entrance pupil and the focused field in a transverse plane in the focal region, i.e., the xy-plane. To analyze the field distribution of special beams in a titled plane, conventional calculations require a stack of slices of fields in the xy-planes plane by plane. Here, we propose a modified FT-based diffraction integral algorithm that exhibits a direct FT connection between the illumination field and the field in an arbitrary plane in the focal volume. As a result, significant time saving is achieved with the proposed algorithm. The algorithm is verified by numerous simulations and should be helpful to quickly design holograms to shape complex focus used in holographic optical tweezers.
入藏号: WOS:000477076200049
ISSN: 0030-4018
eISSN: 1873-0310

第 51 条,共 344 条
标题: A broadband enhanced plasmonic modulator based on double-layer graphene at mid-infrared wavelength
作者: Chi, J (Chi, Jiao); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu)
来源出版物: JOURNAL OF PHYSICS D-APPLIED PHYSICS 卷: 52 期: 44 文献号: 445101 DOI: 10.1088/1361-6463/ab36dc 出版年: OCT 30 2019
摘要: Graphene is as an essential material for light modulation owing to controlling broadband absorption and plasmon excitation. Here, we propose a mid-infrared enhanced plasmonic modulator that integrates double-layer graphene in a reflective structure. It is demonstrated that double-layer graphene can support plasmonic resonances with higher oscillator intensity than single-layer in this modulator. The proposed modulator exhibits a modulation depth up to 21 dB and 3 dB bandwidth of 47.4 GHz over a wide range of wavelength (3.17 mu m to 4.4 mu m). Moreover, the maximum insertion loss of it is barely about 0.27 dB and the minimum of that is about 0.1 dB. This graphene-based modulator, with combined advantages of high modulation depth, low insertion loss and ultrafast modulation speed, holds potential in efficient manipulating MIR lights in free space communication.
入藏号: WOS:000481694000001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
, Chi                  0000-0002-0612-1431

ISSN: 0022-3727
eISSN: 1361-6463
________________________________________
第 52 条,共 344 条
标题: Investigation on the formation and regulation of yttrium aluminosilicate fiber driven by spontaneous element migration
作者: Zhang, YM (Zhang, Yeming); Sun, Y (Sun, Yue); Wen, JX (Wen, Jianxiang); Lv, SC (Lv, Shichao); Xiao, XS (Xiao, Xusheng); Ma, ZJ (Ma, Zhijun); Yang, LY (Yang, Luyun); Bi, G (Bi, Gang); Guo, HT (Guo, Haitao); Qiu, JR (Qiu, Jianrong)
来源出版物: CERAMICS INTERNATIONAL 卷: 45 期: 15 页: 19182-19188 DOI: 10.1016/j.ceramint.2019.06.165 出版年: OCT 15 2019
摘要: In the conventional fiber drawing process, the waveguide parameters (fiber core diameter, refractive index profile, numerical aperture) of the optical fiber are decided (with very limited perturbation range) once the optical and geometric properties of the preform are determined. In comparison, yttrium aluminosilicate (YAS) fibers prepared by "molten core method" (also termed as "melt-in-tube" method) reveal a unique fiber formation process. Although the previous works have shown that the element diffusion plays a significant role in the formation of YAS fiber, the description of this formation process is still vague and the properties of YAS fibers obtained by this method show low controllability in practice, which cannot be explained by elemental diffusion alone. Here, a new model for the formation mechanism of YAS fibers is proposed based on the experimental data, which involves the consideration of interfacial stress during the formation of YAS fibers. The relationship between the refractive index and the element distribution in the YAS fibers was studied. Structural simulation based on the molecular dynamics was also performed to demonstrate the formation mechanism of glassy YAS fiber core.
入藏号: WOS:000483454200125
ISSN: 0272-8842
eISSN: 1873-3956
________________________________________
第 53 条,共 344 条
标题: Fabrication of refractive silicon microlens array with a large focal number and accurate lens profile
作者: Zhou, XJ (Zhou, Xiaojun); Song, AG (Song, Aiguo); Wang, S (Wang, Shuai); Wang, MJ (Wang, Mengjia); Yu, WX (Yu, Weixing)
来源出版物: MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS DOI: 10.1007/s00542-019-04644-4 提前访问日期: OCT 2019
摘要: In this paper, we demonstrate the fabrication of refractive silicon microlens array with a large focal number and almost perfect spherical lens shape. Through a modified thermal reflow, photoresist microlens array of a large focal number is fabricated, which is then transferred into the silicon substrate by ion beam milling. To reach an accurate spherical lens profile, we both theoretically and experimentally study the practical factors that harm the pattern transfer fidelity, which mainly include the etching selectivity and faceting effect. Other secondary etching effects, such as the trenching effect and re-deposition effect, are also discussed. Based on these studies, a silicon microlens array with a focal number of 1.35 has been successfully obtained, with the profile error controlled well-below 0.121 mu m, less than lambda/6 within the whole infrared wavelength band. Besides, the fabricated microlens array exhibits a good uniformity and fine surface smoothness. The fabricated silicon microlens arrays can be applied in minatured infrared and terahertz imaging devices, or used as the master mould for soft lithography.
入藏号: WOS:000489465900001
ISSN: 0946-7076
eISSN: 1432-1858
________________________________________
第 54 条,共 344 条
标题: Influence of energy fluence and overlapping rate of femtosecond laser on surface roughness of Ti-6Al-4V
作者: Yang, Y (Yang, Yong); Lou, R (Lou, Rui); Chen, X (Chen, Xu); Fan, WH (Fan, Wenhui); Bai, J (Bai, Jing); Cao, WW (Cao, Weiwei); Cheng, GH (Cheng, Guanghua); Si, JH (Si, Jinhai)
来源出版物: OPTICAL ENGINEERING 卷: 58 期: 10 文献号: 106107 DOI: 10.1117/1.OE.58.10.106107 出版年: OCT 2019
摘要: The Ti-6Al-4V polished by femtosecond laser processing is first investigated. The surface nanoparticles of Ti-6Al-4V induced by femtosecond laser have been characterized by scanning electron microscopy and energy dispersive spectrometry, and the influence of laser fluence and the overlapping rate of laser beam on surface roughness have also been analyzed. Moreover, the relationship between the laser parameters and the surface roughness of Ti-6Al-4V has been revealed, and the fine surface roughness of Ti-6Al-4V is obtained based on the optimized femtosecond laser processing parameters. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License.
入藏号: WOS:000500957400036
ISSN: 0091-3286
eISSN: 1560-2303
________________________________________
第 55 条,共 344 条
标题: One-dimensional gap solitons in quintic and cubic-quintic fractional nonlinear Schrodinger equations with a periodically modulated linear potential
作者: Zeng, LW (Zeng, Liangwei); Zeng, JH (Zeng, Jianhua)
来源出版物: NONLINEAR DYNAMICS 卷: 98 期: 2 页: 985-995 DOI: 10.1007/s11071-019-05240-x 出版年: OCT 2019
摘要: Competing nonlinearities, such as the cubic (Kerr) and quintic nonlinear terms whose strengths are of opposite signs (the coefficients in front of the nonlinearities), exist in various physical media (in particular, in optical and matter-wave media). A benign competition between self-focusing cubic and self-defocusing quintic nonlinear nonlinearities (known as cubic-quintic model) plays an important role in creating and stabilizing the self-trapping of D-dimensional localized structures, in the contexts of standard nonlinear Schrodinger equation. We incorporate an external periodic potential (linear lattice) into this model and extend it to the space-fractional scenario that begins to surface in very recent years-the nonlinear fractional Schrodinger equation (NLFSE), therefore obtaining the cubic-quintic or the purely quintic NLFSE, and investigate the propagation and stability properties of self-trapped modes therein. Two types of one-dimensional localized gap modes are found, including the fundamental and dipole-mode gap solitons. Employing the techniques based on the linear-stability analysis and direct numerical simulations, we get the stability regions of all the localized modes; and particularly, the anti-Vakhitov-Kolokolov criterion applies for the stable portions of soliton families generated in the frameworks of quintic-only nonlinearity and competing cubic-quintic nonlinear terms.
入藏号: WOS:000496808000009
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ceng, jian hua                  0000-0003-0189-1856

ISSN: 0924-090X
eISSN: 1573-269X
________________________________________
第 56 条,共 344 条
标题: Imaging Correlography Using Ptychography
作者: Li, ZX (Li, Zhixin); Wen, DS (Wen, Desheng); Song, ZX (Song, Zongxi); Jiang, TC (Jiang, Tuochi); Zhang, WK (Zhang, Weikang); Liu, G (Liu, Gang); Wei, X (Wei, Xin)
来源出版物: APPLIED SCIENCES-BASEL 卷: 9 期: 20 文献号: 4377 DOI: 10.3390/app9204377 出版年: OCT 2019
摘要: Featured Application
Space target surveillance is a significant part of space defense, and is also important for maintaining national security. Imaging of the space targets is the direct method used to realize space target recognition. However, for long-range space targets, such as middle-and-high altitude Earth satellites and space debris above 10,000 km, the resolution of the imaging system is required to reach the milliarcsecond (mas) scale to obtain clear images. Because of the limitations of telescope apertures, it is difficult for traditional wavefront imaging to satisfy this requirement. In addition, the amplitude interferometer requires high accuracy from the instrument, which makes it difficult to achieve a long baseline. The proposed ptychographic imaging correlography removes the need to measure the phase information of the object. The ptychographic phase retrieval algorithm is applied to restore the phase data to realize target reconstruction. This has the advantages of low equipment accuracy and insensitivity to atmospheric turbulence. Therefore, the proposed method in this work has great prospects in long-range imaging systems.
Abstract Imaging correlography, an effective method for long-distance imaging, recovers an object using only the knowledge of the Fourier modulus, without needing phase information. It is not sensitive to atmospheric turbulence or optical imperfections. However, the unreliability of traditional phase retrieval algorithms in imaging correlography has hindered their development. In this work, we join imaging correlography and ptychography together to overcome such obstacles. Instead of detecting the whole object, the object is measured part-by-part with a probe moving in a ptychographic way. A flexible optimization framework is proposed to reconstruct the object rapidly and reliably within a few iterations. In addition, novel image space denoising regularization is plugged into the loss function to reduce the effects of input noise and improve the perceptual quality of the recovered image. Experiments demonstrate that four-fold resolution gains are achievable for the proposed imaging method. We can obtain satisfactory results for both visual and quantitative metrics with one-sixth of the measurements in the conventional imaging correlography. Therefore, the proposed imaging technique is more suitable for long-range practical applications.
入藏号: WOS:000496269400180
eISSN: 2076-3417
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第 57 条,共 344 条
标题: Si Photonics for Practical LiDAR Solutions
作者: Sun, XC (Sun, Xiaochen); Zhang, LX (Zhang, Lingxuan); Zhang, QH (Zhang, Qihao); Zhang, WF (Zhang, Wenfu)
来源出版物: APPLIED SCIENCES-BASEL 卷: 9 期: 20 文献号: 4225 DOI: 10.3390/app9204225 出版年: OCT 2019
摘要: In the article the authors discuss light detection and ranging (LiDAR) for automotive applications and the potential roles Si photonics can play in practice. The authors review published research work on Si photonics optical phased array (OPA) and other relevant devices in the past decade with in-depth technical analysis with respect to practical system design considerations. The commercialization status of certain LiDAR technologies is briefly introduced.
入藏号: WOS:000496269400028
eISSN: 2076-3417
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第 58 条,共 344 条
标题: High energy femtosecond laser micromachining with hollow core photonic crystal fiber delivery
作者: Li, F (Li, Feng); Yang, Z (Yang, Zhi); Lv, ZG (Lv, Zhiguo); Wang, YS (Wang, Yishan); Li, QL (Li, Qianglong); Wei, YF (Wei, Yufeng); Yang, Y (Yang, Yang); Yang, XJ (Yang, Xiaojun); Zhao, W (Zhao, Wei)
来源出版物: OPTIK 卷: 194 文献号: UNSP 163093 DOI: 10.1016/j.ijleo.2019.163093 出版年: OCT 2019
摘要: In this paper, we demonstrate a new way to deliver the high energy femtosecond laser with Kagome-type hollow core photonic crystal fiber for micromachining compared to the traditional free space laser delivery. To achieve the high coupling efficiency and overcome the nonlinear effect in the delivery, the coupling system is optimized and the fiber is vacuum pumped to less than 5 mbar. High delivery efficiency more than 90% is achieved. To our best knowledge, this is the highest efficiency of femtosecond laser delivered by Kagome type hollow core fiber. With vacuum pump, we lowered the nonlinear effect and make the laser beam have good beam profile and slightly pulse duration change even in the delivery of laser with the pulse energy of 100 mu J, average power of 20 W, and pulse duration of 234 fs. The whole system is also used to make micromachining of aluminum and stainless steel with good processing quality.
入藏号: WOS:000494476200067
ISSN: 0030-4026
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第 59 条,共 344 条
标题: Percussion drilling on nickel-based alloy with thermal barrier coatings using femtosecond laser
作者: Zhai, ZY (Zhai, Zhaoyang); Wang, WJ (Wang, Wenjun); Mei, XS (Mei, Xuesong); Li, M (Li, Ming); Li, X (Li, Xun)
来源出版物: OPTIK 卷: 194 文献号: UNSP 163066 DOI: 10.1016/j.ijleo.2019.163066 出版年: OCT 2019
摘要: Femtosecond laser with wave length of 800 nm was used to perform percussion drilling experiment on nickel-based alloy with thermal barrier coatings (TBCs) in order to eliminate the damages caused by conventional drilling. Analysis of the experimental results indicated that short pulse duration and high peak power characteristics of femtosecond laser led to good processing effect on nickel-based alloy with TBCs. High quality array of holes with the taper of almost zero was generated, for which the inner diameter was 162 mu m and the aspect ratio was 15:1. Femtosecond laser processing had little influence on elementary components and phase structure of coating. This study provides feasible technique involving the use of femtosecond laser for machining film cooling hole on nickel-based alloy with TBCs.
入藏号: WOS:000494476200043
ISSN: 0030-4026
eISSN: 1618-1336
________________________________________
第 60 条,共 344 条
标题: Integrated Optical Filter Using Spiral-Based Cascaded Mach-Zehnder Interferometers
作者: Ge, ZQ (Ge, Zhiqiang); Zeng, C (Zeng, Chao); Gong, YK (Gong, Yongkang); Zhang, LX (Zhang, Lingxuan); Wang, GX (Wang, Guoxi); Wang, LR (Wang, Leiran); Sun, QB (Sun, Qibing); Si, JH (Si, Jinhai); Zhao, W (Zhao, Wei); Zhang, WF (Zhang, Wenfu)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 5 文献号: 4901013 DOI: 10.1109/JPHOT.2019.2940564 出版年: OCT 2019
摘要: We have proposed a new compact integrated optical filter based on cascaded Mach-Zehnder interferometers (MZIs), and designed corresponding coupling structures without S-bend. The wavelength dependence and fabrication tolerance of coupling structures constructed in straight waveguides and bent waveguides were sufficiently analyzed by the finite-difference time-domain (FDTD) method. The results showed that the curved coupler possesses property of broadband with large fabrication tolerance. Specifically, for the presented 3 dB coupler incorporated with the asymmetric curved waveguides, the deviation of transmission remained below 2% at wavelength from 1.5 to 1.6 mu m, which is greatly helpful to broadband spectral response of cascaded MZIs. By connecting curved couplers with spiral waveguides, a filter by means of two-stages cascaded MZIs was optimally demonstrated to realize a channel spacing of 10 nm. The spiral-based MZIs filter (SBMF) provides a new reference for MZIs filter limited by footprint and wavelength dependence.
入藏号: WOS:000495093900001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zeng, Chao                  0000-0003-0097-6399

ISSN: 1943-0655
eISSN: 1943-0647
________________________________________
第 61 条,共 344 条
标题: All-Fiber Saturable Absorbers for Ultrafast Fiber Lasers
作者: Zhao, W (Zhao, Wei); Chen, GW (Chen, Guangwei); Li, WL (Li, Wenlei); Wang, GM (Wang, Guomei); Zeng, C (Zeng, Chao)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 5 文献号: 7104019 DOI: 10.1109/JPHOT.2019.2941580 出版年: OCT 2019
摘要: ZThe past decade has witnessed tremendous achievements of ultrafast fiber laser technologies due to rapid developments of saturable absorbers (SAs) based on, in particular, nanomaterials such as 0D quantum dot, 1D carbon nanotubes, 2D layered materials, and 3D nanostructures. However, most of those nanomaterials-based SAs are inevitably absence of the high damage threshold and all-fiber integration, therefore challenging their applications on highly integrated and high-energy pulse generations. Recently, the real all-fiber SAs based on the nonlinear multimodal interference (NLMMI) technique using multimode fibers are demonstrated to overcome the above limitations. In this review, a detailed summary of the recent advances in NLMMI-based all-fiber SAs is provided, including the fundamental theory, implementation scenarios, and ultrafast fiber lasers of the all-fiber SAs, covering wide wavelength range of 1, 1.55, and 2 mu m. In addition to the state-of-the-art overview, optical rogue waves in the all-fiber SA-based ultrafast fiber laser are extensively analyzed, which reveals the laser physics behind the dynamics from low-energy to high-energy pulses and directs the design of high-energy ultrafast fiber lasers. The conclusions and perspectives of the all-fiber SAs are also discussed at the end.
入藏号: WOS:000492156400001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zeng, Chao                  0000-0003-0097-6399

ISSN: 1943-0655
eISSN: 1943-0647
________________________________________
第 62 条,共 344 条
标题: Robust Space-Frequency Joint Representation for Remote Sensing Image Scene Classification
作者: Fang, J (Fang, Jie); Yuan, Y (Yuan, Yuan); Lu, XQ (Lu, Xiaoqiang); Feng, YC (Feng, Yachuang)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 10 页: 7492-7502 DOI: 10.1109/TGRS.2019.2913816 出版年: OCT 2019
摘要: Remote sensing image scene classification is a fundamental problem, which aims to label an image with a specific semantic category automatically. Recent progress on remote sensing image scene classification is substantial, benefitting mostly from the powerful feature extraction capability of convolutional neural networks (CNNs). Even though these CNN-based methods have achieved competitive performances, they only construct the representation of the image in location-sensitive space-domain. As a result, their representations are not robust to rotation-variant remote sensing images, which influence the classification accuracy. In this paper, we propose a novel feature representation method by introducing a frequency-domain branch to the traditional only-space-domain architecture. Our framework takes full advantages of discriminative features from space domain and location-robust features from the frequency domain, providing more advanced representations through an additional joint learning module, a property that is critically needed to perform remote sensing image scene classification. Additionally, our method produces satisfactory performances on four public and challenging remote sensing image scene data sets, Sydney, UC-Merced, WHU-RS19, and AID.
入藏号: WOS:000489829200016
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lu, Xiaoqiang                  0000-0002-7037-5188
Fang, Jie                  0000-0002-8325-3905

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 63 条,共 344 条
标题: A Feature Aggregation Convolutional Neural Network for Remote Sensing Scene Classification
作者: Lu, XQ (Lu, Xiaoqiang); Sun, H (Sun, Hao); Zheng, XT (Zheng, Xiangtao)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 10 页: 7894-7906 DOI: 10.1109/TGRS.2019.2917161 出版年: OCT 2019
摘要: Remote sensing scene classification (RSSC) refers to inferring semantic labels based on the content of the remote sensing scenes. Recently, most works take the pretrained convolutional neural network (CNN) as the feature extractor to build a scene representation for RSSC. The activations in different layers of CNN (named intermediate features) contain different spatial and semantic information. Recent works demonstrate that aggregating intermediate features into a scene representation can significantly improve the classification accuracy for RSSC. However, the intermediate features are aggregated by some unsupervised feature encoding methods (e.g., Bag-of-Visual-Words). Little attention has been paid to explore the information of semantic labels for the feature aggregation. In this paper, in order to explore the semantic label information, an end-to-end feature aggregation CNN (FACNN) is proposed to learn a scene representation for RSSC. In FACNN, a supervised convolutional features' encoding module and a progressive aggregation strategy are proposed to leverage the semantic label information to aggregate the intermediate features. The FACNN integrates the feature learning, feature aggregation, and classifier into a unified end-to-end framework for joint training. In FACNN, the scene representation is learned by considering the information of semantic labels, which can result in better performance for RSSC. Extensive experiments on AID, UC-Merged, and WHU-RS19 databases demonstrate that FACNN performs better than several state-of-the-art methods.
入藏号: WOS:000489829200046
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 64 条,共 344 条
标题: Indoor PM2.5 Profiling with a Novel Side-Scatter Indoor Lidar
作者: Qiu, YW (Qiu, Youwei); Tao, S (Tao, Shu); Yun, X (Yun, Xiao); Du, W (Du, Wei); Shen, GF (Shen, Guofeng); Lu, CX (Lu, Cengxi); Yu, XY (Yu, Xinyuan); Cheng, HF (Cheng, Hefa); Ma, JM (Ma, Jianmin); Xue, B (Xue, Bin); Tao, JY (Tao, Jinyou); Dai, JH (Dai, Junhu); Ge, QS (Ge, Quansheng)
来源出版物: ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 卷: 6 期: 10 页: 612-616 DOI: 10.1021/acs.estlett.9b00544 出版年: OCT 2019
摘要: Indoor air pollution dominates respiration exposure because people spend most of their time indoors. Generally, indoor PM2.5 concentrations are monitored at a fixed height in the breathing zone. However, the concentrations of PM2.5 likely vary vertically; thus, the vertical concentration profiles would help improve the understanding of indoor air pollution. Based on the basic principle of bistatic Lidar for boundary aerosol profiling, an indoor Lidar (I-Lidar) was developed to profile the vertical distribution of PM2.5 by imaging the PM2.5 scattering of a vertical laser beam onto a complementary metal oxide semiconductor (CMOS) camera. Unlike bistatic Lidar, the I-Lidar views the vertical laser beam perpendicularly from the side, which enables a high and relatively uniform vertical resolution throughout the profile. The images collected by I-Lidar were adjusted for transmission and scattering attenuation and calibrated against the measured PM2.5 concentrations using an array of PM2.5 sensors. The new device was tested in the field, and the measurements in a living room and kitchen of a rural household revealed the existence of vertical trends and dynamic change of PM2.5 concentrations. Potential applications of the device are discussed.
入藏号: WOS:000489678600008
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Cheng, Hefa         A-1193-2007         0000-0003-4911-6971
SHEN, Guofeng         F-3163-2015         0000-0002-7731-5399

ISSN: 2328-8930
________________________________________
第 65 条,共 344 条
标题: Logic NOT gates of the intensity-noise correlation and squeezing in a diamond nitrogen-vacancy center
作者: Liu, Y (Liu, Yang); Raza, F (Raza, Faizan); Li, KK (Li, Kangkang); Ullah, H (Ullah, Habib); Zhang, YP (Zhang, Yanpeng); Zhang, WF (Zhang, Wenfu); Zhao, W (Zhao, Wei)
来源出版物: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 卷: 36 期: 10 页: 2727-2734 DOI: 10.1364/JOSAB.36.002727 出版年: OCT 1 2019
摘要: Color defects in a diamond nitrogen-vacancy (NV) center represent an important physical system for emergent quantum technologies such as logic gates and registers at room temperature. We realized an optical logic NOT gate by inducing a phase shift in a diamond NV center under nonlinear Kerr effect of spontaneous parametric four-wave mixing (SP-FWM). Also, we discussed the intensity-noise correlation and intensity-difference squeezing of SP-FWM and composite signals (SP-FWM+fluorescence) under self-phase modulation (SPM) and cross-phase modulation (XPM) induced by the nonlinear Kerr effect in V-type and double V-type atomic systems. Our experimental results provide an advanced technique of switching contrast by approximately 90%. Different parameters, such as the power of input laser beam and boxcar gate position, were also configured to control the SPM and XPM, which determine the switching phenomenon for correlation and squeezing. (C) 2019 Optical Society of America
入藏号: WOS:000488515300027
ISSN: 0740-3224
eISSN: 1520-8540
________________________________________
第 66 条,共 344 条
标题: CMOS-compatible high-index doped silica waveguide with an embedded silicon-nanocrystal strip for all-optical analog-to-digital conversion
作者: Li, YH (Li, Yuhua); Zhu, K (Zhu, Kun); Kang, Z (Kang, Zhe); Ho, WL (Ho, Wai Lok); Davidson, R (Davidson, Roy); Lu, C (Lu, Chao); Little, BE (Little, Brent E.); Chu, ST (Chu, Sai Tak)
来源出版物: PHOTONICS RESEARCH 卷: 7 期: 10 页: 1200-1208 DOI: 10.1364/PRJ.7.001200 出版年: OCT 1 2019
摘要: Passive all-optical signal processors that overcome the electronic bottleneck can potentially be the enabling components for the next-generation high-speed and lower power consumption systems. Here, we propose and experimentally demonstrate a CMOS-compatible waveguide and its application to the all-optical analog-to-digital converter (ADC) under the nonlinear spectral splitting and filtering scheme. As the key component of the proposed ADC, a 50 cm long high-index doped silica glass spiral waveguide is composed of a thin silicon-nanocrystal (Si-nc) layer embedded in the core center for enhanced nonlinearity. The device simultaneously possesses low loss (0.16 dB/cm at 1550 nm), large nonlinearity (305 W-1/km at 1550 nm), and negligible nonlinear absorption. A 2-bit ADC basic unit is achieved when pumped by the proposed waveguide structure at the telecom band and without any additional amplification. Simulation results that are consistent with the experimental ones are also demonstrated, which further confirm the feasibility of the proposed scheme for larger quantization resolution. This demonstrated approach enables a fully monolithic solution for all-optical ADC in the future, which can digitize broadband optical signals directly at low power consumption. This has great potential on the applications of high-speed optical communications, networks, and signal processing systems. (C) 2019 Chinese Laser Press
入藏号: WOS:000488619700013
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
HO, Wai Lok                  0000-0002-3486-3600

ISSN: 2327-9125
________________________________________
第 67 条,共 344 条
标题: Compressed Blind Deconvolution and Denoising for Complementary Beam Subtraction Light-Sheet Fluorescence Microscopy
作者: Bai, C (Bai, Chen); Liu, C (Liu, Chao); Jia, H (Jia, Hao); Peng, T (Peng, Tong); Min, JW (Min, Junwei); Lei, M (Lei, Ming); Yu, XH (Yu, Xianghua); Yao, BL (Yao, Baoli)
来源出版物: IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 卷: 66 期: 10 页: 2979-2989 DOI: 10.1109/TBME.2019.2899583 出版年: OCT 2019
摘要: Objective: The side-lobes of a Bessel beam (BB) create a severe out-of-focus background in scanning light-sheet fluorescence microscopy, thereby extremely limiting the axial resolution. The complementary beam subtraction (CBS) method can significantly reduce the out-of-focus background by double scanning a BB and its complementary beam. However, the blurring and noise caused by the system instability during the double scanning and subtraction operations degrade the image quality significantly. Therefore, we propose a compressed blind deconvolution and denoising (CBDD) method that solves this problem. Methods: We use a unified formulation that comprehensively takes advantage of multiple compressed sensing reconstructions and blind sparse representation. Results: The simulations and experiments were performed using the microbeads and model organisms to verify the effectiveness of the proposed method. Compared with the CBS light-sheet method, the proposed CBDD algorithm achieved the gain improvement in the axial and lateral resolution of about 1.81 and 2.22 times, respectively, while the average signal-to-noise ratio (SNR) was increased by about 3 dB. Conclusion: Accordingly, the proposed method can suppress the noise level, enhance the SNR, and recover the degraded resolution simultaneously. Significance: The obtained results demonstrate the proposed CBDD algorithm is well suited to improve the imaging performance of the CBS light-sheet fluorescence microscopy.
入藏号: WOS:000487192000030
PubMed ID: 30794159
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yu, Xianghua                  0000-0002-7447-1396
Peng, Tong                  0000-0003-0373-5136

ISSN: 0018-9294
eISSN: 1558-2531
________________________________________
第 68 条,共 344 条
标题: From Deterministic to Generative: Multimodal Stochastic RNNs for Video Captioning
作者: Song, JK (Song, Jingkuan); Guo, YY (Guo, Yuyu); Gao, LL (Gao, Lianli); Li, XL (Li, Xuelong); Hanjalic, A (Hanjalic, Alan); Shen, HT (Shen, Heng Tao)
来源出版物: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 卷: 30 期: 10 页: 3047-3058 DOI: 10.1109/TNNLS.2018.2851077 出版年: OCT 2019
摘要: Video captioning, in essential, is a complex natural process, which is affected by various uncertainties stemming from video content, subjective judgment, and so on. In this paper, we build on the recent progress in using encoder-decoder framework for video captioning and address what we find to be a critical deficiency of the existing methods that most of the decoders propagate deterministic hidden states. Such complex uncertainty cannot be modeled efficiently by the deterministic models. In this paper, we propose a generative approach, referred to as multimodal stochastic recurrent neural networks (MS-RNNs), which models the uncertainty observed in the data using latent stochastic variables. Therefore, MS-RNN can improve the performance of video captioning and generate multiple sentences to describe a video considering different random factors. Specifically, a multimodal long short-term memory (LSTM) is first proposed to interact with both visual and textual features to capture a high-level representation. Then, a backward stochastic LSTM is proposed to support uncertainty propagation by introducing latent variables. Experimental results on the challenging data sets, microsoft video description and microsoft research videoto-text, show that our proposed MS-RNN approach outperforms the state-of-the-art video captioning benchmarks.
入藏号: WOS:000487199000014
PubMed ID: 30130235
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong                  0000-0002-0019-4197
song, jingkuan                  0000-0002-2549-8322
Wettergren, Thomas                  0000-0002-6623-8412

ISSN: 2162-237X
eISSN: 2162-2388
________________________________________
第 69 条,共 344 条
标题: Range-gated imaging in turbid conditions using a combination of intensity and polarization information
作者: Ren, W (Ren, Wei); Guan, JG (Guan, Jinge); Liu, JH (Liu, Jiahang); Chen, JY (Chen, Junyu); Feng, XS (Feng, Xiaoshan)
来源出版物: PHYSICA SCRIPTA 卷: 94 期: 10 文献号: 105505 DOI: 10.1088/1402-4896/ab2683 出版年: OCT 2019
摘要: Polarization of light is introduced into range-gated imaging (RGI) for target detection and recognition in turbid conditions. The polarimetric RGI system can obtain both intensity and polarization information on objects. The experimental results show that an intensity-based image, when the target part and the background part of an object have similar reflective characteristic, can reveal the contours of the object by minimizing the effect of backscattering from the medium, and a polarization-based image can highlight the target part by common-mode rejection of the background. Furthermore, intensity and polarization components are combined to describe the scene systematically. Four methods-Laplacian pyramid, discrete wavelet transform, contourlet transform and nonsubsampled contourlet transform-are used for image fusion. Favourable information represented in each image can be extracted from image fusion for target detection and recognition. Objective evaluation indices are applied to compare the performance of different image fusion methods.
入藏号: WOS:000480297800001
ISSN: 0031-8949
eISSN: 1402-4896
________________________________________
第 70 条,共 344 条
标题: Double-dressing tri and quad-photon correlations in spontaneous six and eight-wave mixing
作者: Li, YM (Li, Yameng); Feng, Y (Feng, Yuan); Li, W (Li, Wei); Li, KK (Li, Kangkang); Liu, Y (Liu, Yang); Lan, YW (Lan, Yuwei); Zhang, YP (Zhang, Yanpeng)
来源出版物: PHYSICA SCRIPTA 卷: 94 期: 10 文献号: 105802 DOI: 10.1088/1402-4896/ab1abb 出版年: OCT 2019
摘要: The generation of a nonclassical multi-photon has aroused renewed interest in recent years. Here, we propose a new method to generate tri-photon and quad-photon correlations in time via a double-dressing spontaneous six-wave mixing and eight-wave mixing process in an atomic ensemble, respectively. When we only consider the nonlinear optical response, the coincidence counts of tri and quad photon serves as damped coherent Rabi oscillation. The coincident count of tri (quad) photon contains three (four) conditional two-photon correlation with 10 or 30 (26, 28 or 38) periods, corresponding to 11 or 19 (18 or 20) modes. These mode and periods of tri and quad photon result from destructive interference from the possible 4 or 8 six wave and 18 eight wave coherent channels, respectively. In addition, for tri-photon, the greater double-dressing field strength is, the fewer the number of periods are. The coherent times are also controlled by the double-dressing effect. Such results have potential applications in multi-mode quantum communication and quantum network.
入藏号: WOS:000478723300001
ISSN: 0031-8949
eISSN: 1402-4896
________________________________________
第 71 条,共 344 条
标题: Detection of ships in inland river using high-resolution optical satellite imagery based on mixture of deformable part models
作者: Song, PF (Song, Pengfei); Qi, L (Qi, Lei); Qian, XM (Qian, Xueming); Lu, XQ (Lu, Xiaoqiang)
来源出版物: JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING 卷: 132 页: 1-7 DOI: 10.1016/j.jpdc.2019.04.013 出版年: OCT 2019
摘要: Ship detection using optical satellite imagery is of great significance in many applications such as traffic surveillance, pollution monitoring, etc. So far, a lot of ship detection methods have been developed for images covering open sea, offshore area and harbors. Compared to the ship detection in sea and offshore area, it is more difficult to detect ships in inland river due to several challenges. First of all, many ships in inland river are clustered together and hard to be separated from each other. Secondly, ships lying alongside the pier are very likely to be recognized as part of the pier. Thirdly, ships in inland river is usually smaller than those in the sea. A hierarchical method is proposed to detect the ships in inland river in this paper. The Regions of Interest (ROIs) are firstly extracted based on water land segmentation using multi-spectral information. Then two kinds of ship candidates are extracted based on the panchromatic band. The isolated ships are detected by analyzing the shape of connected components and the clustered ships are detected by using mixtures multi-scale Deformable Part Models (DPM) and Histogram of Oriented Gradient (HOG). At last, a Back Propagation Neural Network (BPNN) is trained to classify the ship candidates using the multi-spectral bands. The experiments using Quickbird satellite images show that our approach is effective in ship detection and performs particularly well in separating the ships clustered together and staying alongside the pier. (C) 2019 Elsevier Inc. All rights reserved.
入藏号: WOS:000476580400001
ISSN: 0743-7315
eISSN: 1096-0848
________________________________________
第 72 条,共 344 条
标题: Bi-directional reflectance and polarization measurements of pulse-laser irradiated airless body analog materials
作者: Jiang, T (Jiang, Te); Zhang, H (Zhang, Hao); Yang, YZ (Yang, Yazhou); Hu, XY (Hu, Xiaoyi); Ma, P (Ma, Pei); Sun, YX (Sun, Yuxue); Britt, D (Britt, Daniel); Wang, WG (Wang, Weigang); Lu, XP (Lu, Xiaoping); Huang, JC (Huang, Jiangchuan); Hsu, WB (Hsu, Weibiao); Mei, B (Mei, Bao); Wei, RY (Wei, Ruyi)
来源出版物: ICARUS 卷: 331 页: 127-147 DOI: 10.1016/j.icarus.2019.05.022 出版年: OCT 2019
摘要: Space weathering (SW) processes including solar wind irradiation and micrometeorite bombardment produce nano-phase iron (npFe) and amorphous layers that redden and darken the visible and near-infrared (VNIR) reflectance spectra of the surface of airless bodies. To understand how SW may affect the directional reflectance and polarization properties of regolith layers, we carried out pulsed laser irradiation experiments to simulate micrometeorite bombardment process on olivine (OL), orthopyroxene (OPX), anorthosite (AN), ilmenite (ILM), and JSC-1A Lunar Regolith Simulant (LRS). All samples have been equalized with a size distribution of (< 45 mu m) and the unsieved LRS with (< 1 mm) was also used. Depending on each samples difficulty level of weathering, 2 to 8 irradiations with single pulse energy of 50 mJ were used in the irradiations. We measured the spectral reflectance from 0.5 to 25 mu m, bi-directional reflectance distribution function (BRDF) and polarization phase curves at 0.633 mu m of the samples before and after irradiations. Scanning electron microscopic images show that the irradiated samples become rougher with produced melts and agglutinates. The VNIR reflectance spectra of all irradiated samples show prominent darkening and reddening, except for the unsieved LSR sample which shows spectral blueing. Compared to that of the original samples, the BRDF of irradiated OL and OPX have both enhanced back-and forward-scattering components, while the other 4 samples have enhanced back scattering but nearly unchanged (AN, ILM, JSC-1A (< 45 mu m)) or decreased (JSC-1A (< 1 mm)) forward scattering. In general, the irradiated samples have larger positive polarization values DOPmax as compared to the original samples, consistent with the Umov law prediction. Within measurement uncertainties, the irradiated samples did not show systematic changes in the minimum polarization value DOPmin and the polarization inversion angle alpha(inv) Using OL as an example, numerical radiative transfer computations verified that, the BRDF of olivine grains with npFe distributed uniformly inside the grains or coated with npFe have enhanced back-and forward scattering components as compared with that of the original grains, consistent with measurement results. A 5-parameter Hapke photometric model inversion has shown that all sample grains except OPX have become more backscattering (with smaller asymmetry parameters) upon the strongest irradiation as compared with the original ones. These results indicate that the directional reflectance properties of space weathered regolith grains of airless bodies may be more backscattering than that of fresh materials.
入藏号: WOS:000473554600012
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yang, Yazhou         H-1646-2018         0000-0002-9848-4650

ISSN: 0019-1035
eISSN: 1090-2643
________________________________________
第 73 条,共 344 条
标题: Minimized Laplacian residual interpolation for DoFP polarization image demosaicking
作者: Jiang, TC (Jiang, Tuochi); Wen, DS (Wen, Desheng); Song, ZX (Song, Zongxi); Zhang, WK (Zhang, Weikang); Li, ZX (Li, Zhixin); Wei, X (Wei, Xin); Liu, G (Liu, Gang)
来源出版物: APPLIED OPTICS 卷: 58 期: 27 页: 7367-7374 DOI: 10.1364/AO.58.007367 出版年: SEP 20 2019
摘要: Division of focal plane (DoFP) polarization imaging sensors have the distinct advantage of acquiring temporally synchronized Stokes vector in one scene. The sensors' spatially modulated arrangement of a micropolarization array results in loss of spatial resolution and instantaneous field-of-overview errors. Polarization demosaicking (PDM) methods are often utilized to address these drawbacks and achieve the goal of recovering missing polarization information. In this paper, we propose minimized Laplacian polarization residual interpolation for PDM. The Laplacian energy is introduced to improve the interpolation accuracy. We employ interchannel correlation and a guided filter to generate precise tentative estimates and the interpolation performed in the residual domain, where the residuals are the differences between observed values and tentative estimates. Experiments demonstrate that the proposed algorithm provides superior performance in terms of mean average error and peak signal- to-noise ratio. (C) 2019 Optical Society of America
入藏号: WOS:000487248800012
PubMed ID: 31674382
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Jiang, Tuochi                  0000-0001-8004-3665
Zhang, Weikang                  0000-0003-2279-3294

ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 74 条,共 344 条
标题: Efficient light focusing through an MMF based on two-step phase shifting and parallel phase compensating
作者: Chen, H (Chen, Hui); Geng, Y (Geng, Yi); Xu, CF (Xu, Chengfang); Zhuang, B (Zhuang, Bin); Ju, HJ (Ju, Haijuan); Ren, LY (Ren, Liyong)
来源出版物: APPLIED OPTICS 卷: 58 期: 27 页: 7552-7557 DOI: 10.1364/AO.58.007552 出版年: SEP 20 2019
摘要: Based on a parallel phase compensation scheme, we propose an efficient wavefront shaping method using a spatial light modulator (SLM) for quickly generating a series of focused spots through a multimode fiber (MMF). The compensated phase mask obtained by a two-step phase-shifting technique is loaded to the SLM for generating a focused spot at an arbitrary target position out of the fiber facet. Furthermore, the parallel algorithm we present makes it possible to obtain a series of compensated phase masks, which could be used to generate a series of focused spots at different locations. We experimentally obtained 100 tightly focused spots, with an average focused efficiency of 21.60% and an average focused diameter of 1.9240 mu m, and only one-time parallel-compensated phase retrieval is required without multiple iteration optimization. (C) 2019 Optical Society of America
入藏号: WOS:000487248800037
PubMed ID: 31674407
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 75 条,共 344 条
标题: L-band mode-locked femtosecond fiber laser with gigahertz repetition rate
作者: Song, JZ (Song, Jiazheng); Liu, YS (Liu, Yuanshan); Zhang, JG (Zhang, Jianguo)
来源出版物: APPLIED OPTICS 卷: 58 期: 27 页: 7577-7581 DOI: 10.1364/AO.58.007577 出版年: SEP 20 2019
摘要: We demonstrate an L-band passively mode-locked femtosecond fiber laser with a fundamental repetition rate of 1.013 GHz based on a semiconductor saturable absorber mirror. Compared with other reported L-band fiber lasers that use overlong Er-doped fiber, the laser here consists of 10 cm heavily doped fiber to increase the fundamental pulse repetition rate to gigahertz level. An output ratio as low as 0.2% is used to make the central wavelength up to 1.6 mu m. The laser operates at the soliton regime with a 3 dB spectral bandwidth of 13.6 nm and a pulse duration of 229 fs. (C) 2019 Optical Society of America
入藏号: WOS:000487248800041
PubMed ID: 31674410
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 76 条,共 344 条
标题: Orthogonal sparse fractal coding algorithm based on image texture feature
作者: Cao, J (Cao, Jian); Zhang, AH (Zhang, Aihua); Shi, L (Shi, Lei)
来源出版物: IET IMAGE PROCESSING 卷: 13 期: 11 页: 1872-1879 DOI: 10.1049/iet-ipr.2019.0085 出版年: SEP 19 2019
摘要: Fractal image compression coding algorithm is a novel image compression technology; however, the long encoding time and unacceptable image reconstruction quality remain the primary obstacles in practical application. The purpose of this study is to improve the coding quality from the perspective of grey level transform and feature extraction. In this study, a novel orthogonal sparse fractal coding algorithm based on image texture feature is proposed. The authors define a normalised version as the new grey description feature of the image block so that two improved methods are scientifically combined in theory and algorithm. First, orthogonal sparse grey level transform based on sparse decomposition improves image reconstruction quality and decoding speed. Then, the similarity measure matrix, which stores the variance feature between range blocks and domain blocks, is used to reduce redundancies and encoding time. Simulation results show that the proposed algorithm in this study can obtain better image reconstruction quality and speed up encoding time significantly as compared to the conventional fractal coding schemes.
入藏号: WOS:000487789000007
ISSN: 1751-9659
eISSN: 1751-9667
________________________________________
第 77 条,共 344 条
标题: Reconfigurable snapshot polarimetric imaging technique through spectral-polarization filtering
作者: Liang, J (Liang, Jian); Tian, XB (Tian, Xiaobo); Ju, HJ (Ju, Haijuan); Wang, DD (Wang, Daodang); Wu, H (Wu, Heng); Ren, LY (Ren, Liyong); Liang, RG (Liang, Rongguang)
来源出版物: OPTICS LETTERS 卷: 44 期: 18 页: 4574-4577 DOI: 10.1364/OL.44.004574 出版年: SEP 15 2019
摘要: In this Letter, we propose a simple, low-cost, reconfigurable snapshot polarimetric imaging technique for a color camera to measure polarization properties with spectral-polarization filters. Experimental results demonstrate the unique capabilities, such as obtaining circular or elliptical polarized information in a snapshot, that are not available from commercial polarization cameras and other polarization imaging techniques. (C) 2019 Optical Society of America
入藏号: WOS:000485817500036
PubMed ID: 31517934
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ren, li yong         F-5518-2014         0000-0002-7547-7511

ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 78 条,共 344 条
标题: Accurate optical vector network analyzer based on optical double-sideband suppressed carrier modulation
作者: Dai, J (Dai, Jian); Chen, ZH (Chen, Zenghui); Wang, XY (Wang, Xiaoyang); Ye, L (Ye, Long); Zhang, T (Zhang, Tian); Xu, K (Xu, Kun)
来源出版物: OPTICS COMMUNICATIONS 卷: 447 页: 61-66 DOI: 10.1016/j.optcom.2019.04.019 出版年: SEP 15 2019
摘要: A high-accuracy optical vector network analysis (OVNA) based on optical suppressed carrier double-sideband (DSB) modulation and the Pound Drever Hall (PDH) technique is proposed and demonstrated. The accurate and stable frequency responses can be achieved by transmitting the optical carrier suppressed DSB modulation signals through the DUT, and then detecting the reflected signals. Compared with the traditional DSB-based OVNA, the measurement accuracy is improved by eliminating the errors caused by the even-order sidebands. Furthermore, the stability of the OVNA system can be kept by using the PDH feedback loop. An experiment is accomplished. The frequency responses of the FP interferometer are achieved with little measurement error induced by high-order sidebands, and no repeated frequency response appears even when the test time reaches up to 30 min. This novel method is simple and accurate, and would be used for charactering the symmetric ultra-high Q optical devices.
入藏号: WOS:000471197400012
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 79 条,共 344 条
标题: Nonmechanical two-user tracking method of space-polarization division using the liquid crystal optical phased array
作者: Guo, HR (Guo, Hongru); Wang, XR (Wang, Xiangru); Liu, XP (Liu, Xiaopeng); He, XX (He, Xiaoxian); Wu, L (Wu, Liang); Huang, XN (Huang, Xinning); Xie, XP (Xie, Xiaoping); Tan, QG (Tan, Qinggui); Cao, J (Cao, Jie); Xie, W (Xie, Wen)
来源出版物: OPTICS COMMUNICATIONS 卷: 447 页: 74-79 DOI: 10.1016/j.optcom.2019.05.005 出版年: SEP 15 2019
摘要: We propose a two-user tracking method called space-polarization division to enable simultaneously multiple terminals tracking in the field of free space laser communications. This method is based on the nonmechanical beam steering device of liquid crystal optical phased array, which is capable of continuously laser beam pointing and multiple beams generating. An optical architecture of two-user access is presented to show a one-to-two communication link between the relay satellite terminal and user terminals. The two-user tracking strategy is modeled numerically and experimentally verified to show the feasible and agile two-user tracking with a good accuracy less than 50 microradians which meet the requirements of coarse tracking.
入藏号: WOS:000471197400014
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 80 条,共 344 条
标题: Impact of various parameters on nanostructures fabrication mechanism on silicon surface with AFM tip induced local anodic oxidation
作者: Wang, XW (Wang, Xuewen); Theogene, B (Theogene, Barayavuga); Mei, HH (Mei, Huanhuan); Zhang, JW (Zhang, Jianwei); Huang, CC (Huang, Chenchen); Ren, XY (Ren, Xiaoying); Xu, MX (Xu, Muxun)
来源出版物: FERROELECTRICS 卷: 549 期: 1 特刊: SI 页: 70-77 DOI: 10.1080/00150193.2019.1592545 出版年: SEP 10 2019
摘要: The AFM tip induced local anodic oxidation (LAO) nanolithography is capable of manufacturing nanometer scale structures and devices for future generation. Experimental studies of LAO on silicon surface, implemented in atmospheric environment by AFM, are presented in this paper. A series of nanostructures with complex patterns was fabricated and analyzed by AFM. The results indicated that various of parameters, such as the applied voltage, pulse time, and ambient humidity, have a strong impact on the height of the nanostructures generated in this way. An advantage of the presented approach is to be utilized in future processing steps in the same environment.
入藏号: WOS:000494798800008
ISSN: 0015-0193
eISSN: 1563-5112
________________________________________
第 81 条,共 344 条
标题: Research on the mechanism of micromachining of CVD diamond by femtosecond laser
作者: Sun, Y (Sun, Yu); Dou, J (Dou, Jian); Xu, MX (Xu, Muxun); Cui, JL (Cui, Jianlei); Mei, XS (Mei, Xuesong); Wang, WJ (Wang, Wenjun); Gao, M (Gao, Meng)
来源出版物: FERROELECTRICS 卷: 549 期: 1 特刊: SI 页: 266-275 DOI: 10.1080/00150193.2019.1592569 出版年: SEP 10 2019
摘要: Diamond is an excellent material in terms of hardness, thermal conductivity and chemical stability. In order to broaden its application area, the interaction mechanism of CVD diamond processed by femtosecond laser is analyzed based on laser micromachining technology. Through the threshold theory, the ablation threshold of CVD diamond is calculated. At the same time, the graphitization phase transition occurred in the diamond. The internal elements before and after the ablation of diamond by femtosecond laser are characterized by X-ray energy spectrum analysis. The changes of element content and bonding form are analyzed, and the relevant graphitization mechanism is revealed.
入藏号: WOS:000494798800030
ISSN: 0015-0193
eISSN: 1563-5112
________________________________________
第 82 条,共 344 条
标题: Elastic bending of variable curvature mirrors: validation of a simplified analytical method
作者: Xie, XP (Xie, Xiaopeng); Hugot, E (Hugot, Emmanuel); Li, C (Li, Chuang); Xu, L (Xu, Lang); Lemared, S (Lemared, Sabri); Liu, MY (Liu, Meiying); Fan, XW (Fan, Xuewu); Zhao, H (Zhao, Hui)
来源出版物: APPLIED OPTICS 卷: 58 期: 26 页: 7121-7126 DOI: 10.1364/AO.58.007121 出版年: SEP 10 2019
摘要: This work explores the variable curvature mirror's (VCM) elastic bending rules through modeling it as a thin elastic plate with an exponential thickness distribution actuated with a uniform pressure under simply supported boundary conditions. By using the small-parameter method, the general analytical expression of a plate's deflection is worked out. The results calculated by the analytical solution are compared to the finite element analysis of a VCM model with the same specific parameters. We demonstrate that the two have a good correlation with the each other. This analytical solution is an effective way to predict a VCM's deflection. (C) 2019 Optical Society of America
入藏号: WOS:000485128500016
PubMed ID: 31503983
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 83 条,共 344 条
标题: Continuous artificial synthesis of glucose precursor using enzyme-immobilized microfluidic reactors
作者: Zhu, YJ (Zhu, Yujiao); Huang, ZY (Huang, Ziyu); Chen, QM (Chen, Qingming); Wu, Q (Wu, Qian); Huang, XW (Huang, Xiaowen); So, PK (So, Pui-Kin); Shao, LY (Shao, Liyang); Yao, ZP (Yao, Zhongping); Jia, YW (Jia, Yanwei); Li, ZH (Li, Zhaohui); Yu, WX (Yu, Weixing); Yang, Y (Yang, Yi); Jian, AQ (Jian, Aoqun); Sang, SB (Sang, Shengbo); Zhang, WD (Zhang, Wendong); Zhang, XM (Zhang, Xuming)
来源出版物: NATURE COMMUNICATIONS 卷: 10 文献号: 4049 DOI: 10.1038/s41467-019-12089-6 出版年: SEP 6 2019
摘要: Food production in green crops is severely limited by low activity and poor specificity of D-ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) in natural photosynthesis (NPS). This work presents a scientific solution to overcome this problem by immobilizing RuBisCO into a microfluidic reactor, which demonstrates a continuous production of glucose precursor at 13.8 mu mol g(-1) RuBisCO min(-1) from CO2 and ribulose-1,5-bisphosphate. Experiments show that the RuBisCO immobilization significantly enhances enzyme stabilities (7.2 folds in storage stability, 6.7 folds in thermal stability), and also improves the reusability (90.4% activity retained after 5 cycles of reuse and 78.5% after 10 cycles). This work mimics the NPS pathway with scalable microreactors for continuous synthesis of glucose precursor using very small amount of RuBisCO. Although still far from industrial production, this work demonstrates artificial synthesis of basic food materials by replicating the light-independent reactions of NPS, which may hold the key to food crisis relief and future space colonization.
入藏号: WOS:000484599200001
PubMed ID: 31492867
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yao, Zhong-Ping         K-2117-2014         0000-0003-3555-9632
Chen, Qingming                  0000-0003-1120-0545
Zhu, Yujiao                  0000-0002-9355-2159
Shao, Liyang         B-2921-2009         0000-0003-1272-1959

ISSN: 2041-1723
________________________________________
第 84 条,共 344 条
标题: Highly reconfigurable hybrid laser based on an integrated nonlinear waveguide
作者: Aadhi, A (Aadhi, A.); Kovalev, AV (Kovalev, Anton, V); Kues, M (Kues, Michael); Roztocki, P (Roztocki, Piotr); Reimer, C (Reimer, Christian); Zhang, YB (Zhang, Yanbing); Wang, T (Wang, Tao); Little, BE (Little, Brent E.); Chu, ST (Chu, Sai T.); Wang, ZM (Wang, Zhiming); Moss, DJ (Moss, David J.); Viktorov, EA (Viktorov, Evgeny A.); Morandotti, R (Morandotti, Roberto)
来源出版物: OPTICS EXPRESS 卷: 27 期: 18 页: 25251-25264 DOI: 10.1364/OE.27.025251 出版年: SEP 2 2019
摘要: The ability of laser systems to emit different adjustable temporal pulse profiles and patterns is desirable for a broad range of applications. While passive mode-locking techniques have been widely employed for the realization of ultrafast laser pulses with mainly Gaussian or hyperbolic secant temporal profiles, the generation of versatile pulse shapes in a controllable way and from a single laser system remains a challenge. Here we show that a nonlinear amplifying loop mirror (NALM) laser with a bandwidth-limiting filter (in a nearly dispersion-free arrangement) and a short integrated nonlinear waveguide enables the realization and distinct control of multiple mode-locked pulsing regimes (e.g., Gaussian pulses, square waves, fast sinusoidal-like oscillations) with repetition rates that are variable from the fundamental (7.63 MHz) through its 205th harmonic (1.56 GHz). These dynamics are described by a newly developed and compact theoretical model, which well agrees with our experimental results. It attributes the control of emission regimes to the change of the NALM response function that is achieved by the adjustable interplay between the NALM amplification and the nonlinearity. In contrast to previous square wave emissions, we experimentally observed that an Ikeda instability was responsible for square wave generation. The presented approach enables laser systems that can be universally applied to various applications, e.g., spectroscopy, ultrafast signal processing and generation of non-classical light states. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000484366700033
PubMed ID: 31510400
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Viktorov, Evgeny         AAH-3699-2019         
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
Kovalev, Anton V.         F-1897-2014         0000-0001-7848-8526

ISSN: 1094-4087
________________________________________
第 85 条,共 344 条
标题: A Molecular Dynamics Study on Self-Assembly of Single-Walled Carbon Nanotubes: From Molecular Morphology and Binding Energy
作者: Zhang, JW (Zhang, Jianwei); Cui, JL (Cui, Jianlei); Cheng, Y (Cheng, Yang); Wang, WJ (Wang, Wenjun); He, XQ (He, Xiaoqiao); Mei, XS (Mei, Xuesong)
来源出版物: ADVANCED MATERIALS INTERFACES 卷: 6 期: 19 文献号: 1900983 DOI: 10.1002/admi.201900983 提前访问日期: SEP 2019 出版年: OCT 2019
摘要: Molecular dynamics simulations are used to reveal the adsorption behavior of modified single-walled carbon nanotubes (M-SWNTs) on the functionalized surfaces (F-surfaces) bound to a silicon dioxide substrate, in order to illustrate the mechanism of patterned self-assembly of SWNTs on the atomic scale. Noncovalent modification strategy with surfactants is adopted to investigate the structural transition of the surfactant on SWNTs in aqueous solution. Core/shell hybrid structures are formed ultimately by the surfactant scrolling onto SWNTs periphery. Two different kinds of silanes are used to control the wettability of the F-surfaces from hydrophobic to hydrophilic. An excluded-volume constraints algorithm is employed to calculate the global energy minimum to rationalize the driving force controlling the behavior evolution. The mechanisms for self-assembly are illustrated in two segments in detail that the electrostatic attraction starts the self-assembly program on the hydrophilic surface, while van der Waals interaction plays an important role in the behavior of nonassembly to the hydrophobic surface. The results are not only helpful to understand many phenomena in the self-assembly process on the atomic scale but also will provide meaningful guidance in fabrication of SWNTs patterns to keep fidelity.
入藏号: WOS:000484729300001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhang, Jianwei                  0000-0002-3137-0763

ISSN: 2196-7350
________________________________________
第 86 条,共 344 条
标题: Label-free detecting oligonucleotide hybridization melting temperature in real-time with a reflectometric interference spectroscopy-based nanosensor system
作者: Lu, Y (Lu, Yao); Sun, D (Sun, Dan); Wang, KG (Wang, Kaige); Bai, XH (Bai, Xiaohong); Zhang, C (Zhang, Chen); Zhao, W (Zhao, Wei); Feng, XQ (Feng, Xiaoqiang); Bai, JT (Bai, Jintao)
来源出版物: OPTIK 卷: 192 文献号: UNSP 162903 DOI: 10.1016/j.ijleo.2019.06.003 出版年: SEP 2019
摘要: The accurate determination of melting temperature (T-m) of oligonucleotide hybridization is the primary for various biosensors based on the technique of using surface-tethered nucleic acids as probes. In this paper, a new type of nanosensor based on the reflectometric interference spectroscopy (RIFS) was proposed to determine the T-m in real time. A composite solid nanostructure, i.e., a nanoporous anodic alumina film with a 15 nm top layer of gold sputtered on surface, was employed as the substrate of the RIFS-based nanosensor, and a 30 bp oligonucleotide molecule was bond to the inner wall of pores and hybridized, and then its T-m was detected with raising temperature. The experimental data showed that there were obvious signs of dsDNA molecules denatured and melted into ssDNA molecules at 95 degrees C, which was highly consistent with the theoretical analysis. The cost-effective RIFS nanosensor has excellent thermal and physicochemical stabilities, higher determination accuracy, and great potential in the field of biomolecule research.
入藏号: WOS:000494471400006
ISSN: 0030-4026
________________________________________
第 87 条,共 344 条
标题: Design of mirror assembly and surface simulation for CPA
作者: Xu, GZ (Xu, Guangzhou); Zhao, XD (Zhao, Xiaodong); Liu, MX (Liu, Minxia); Liu, Y (Liu, Ying)
来源出版物: OPTIK 卷: 192 文献号: UNSP 162939 DOI: 10.1016/j.ijleo.2019.162939 出版年: SEP 2019
摘要: Mirror assembly is the important front module for the coarse pointing element of satellite laser communication. The structural and environmental adaption of the mirror assembly has a great influence for the performance of the laser communication system. To solve the design problem of the mirror assembly, the design of SiC mirror assembly and surface simulation for CPA is researched. First, the lightweight structure of SiC mirror is designed. Besides, to reduce the influence for the mirror surface change caused by the mismatching of different linear expansion coefficient, the flexible supporting structure is designed to realize the connection between the mirror and supporting structure. Second, the high-precision algorithm based on discrete error elimination technique for surface parameter of mirror is proposed and the correctness of the algorithm is validated. The validation result demonstrated the precision of proposed algorithm is higher and can satisfy the engineering demands. At last, the surface data of finite element analysis for the SiC mirror is processed by the developed program with high-precision algorithm; the surface parameter of mirror is obtained under the loadcases with gravity and thermal deformation. Based on the calculation result of surface parameter, the structural design of mirror assembly for CPA is verified and the fundamental data is provided to revise the structural design parameter of the mirror. A new technical reference is presented for the supporting structure design of mirror and the simulation technique of optical surface.
入藏号: WOS:000494471400028
ISSN: 0030-4026
________________________________________
第 88 条,共 344 条
标题: Spatial Structure Preserving Feature Pyramid Network for Semantic Image Segmentation
作者: Yuan, Y (Yuan, Yuan); Fang, J (Fang, Jie); Lu, XQ (Lu, Xiaoqiang); Feng, YC (Feng, Yachuang)
来源出版物: ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS 卷: 15 期: 3 文献号: 73 DOI: 10.1145/3321512 出版年: SEP 2019
摘要: Recently, progress on semantic image segmentation is substantial, benefiting from the rapid development of Convolutional Neural Networks. Semantic image segmentation approaches proposed lately have been mostly based on Fully convolutional Networks (FCNs). However, these FCN-based methods use large receptive fields and too many pooling layers to depict the discriminative semantic information of the images. Specifically, on one hand, convolutional kernel with large receptive field smooth the detailed edges, since too much contexture information is used to depict the "center pixel." However, the pooling layer increases the receptive field through zooming out the latest feature maps, which loses many detailed information of the image, especially in the deeper layers of the network. These operations often cause low spatial resolution inside deep layers, which leads to spatially fragmented prediction. To address this problem, we exploit the inherent multi-scale and pyramidal hierarchy of deep convolutional networks to extract the feature maps with different resolutions and take full advantages of these feature maps via a gradually stacked fusing way. Specifically, for two adjacent convolutional layers, we upsample the features from deeper layer with stride of 2 and then stack them on the features from shallower layer. Then, a convolutional layer with kernels of 1 x 1 is followed to fuse these stacked features. The fused feature preserves the spatial structure information of the image; meanwhile, it owns strong discriminative capability for pixel classification. Additionally, to further preserve the spatial structure information and regional connectivity of the predicted category label map, we propose a novel loss term for the network. In detail, two graph model-based spatial affinity matrixes are proposed, which are used to depict the pixel-level relationships in the input image and predicted category label map respectively, and then their cosine distance is backward propagated to the network. The proposed architecture, called spatial structure preserving feature pyramid network, significantly improves the spatial resolution of the predicted category label map for semantic image segmentation. The proposed method achieves state-of-the-art results on three public and challenging datasets for semantic image segmentation.
入藏号: WOS:000494301200005
ISSN: 1551-6857
eISSN: 1551-6865
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第 89 条,共 344 条
标题: 1.34 mu m Q-Switched Nd:YVO4 Laser with a Reflective WS2 Saturable Absorber
作者: Wang, TJ (Wang, Taijin); Wang, YG (Wang, Yonggang); Wang, J (Wang, Jiang); Bai, J (Bai, Jing); Li, GY (Li, Guangying); Lou, R (Lou, Rui); Cheng, GH (Cheng, Guanghua)
来源出版物: NANOMATERIALS 卷: 9 期: 9 文献号: 1200 DOI: 10.3390/nano9091200 出版年: SEP 2019
摘要: In this work, a Tungsten disulfide (WS2) reflective saturable absorber (SA) fabricated using the Langmuir-Blodgett technique was used in a solid state Nd:YVO4 laser operating at 1.34 mu m. A Q-switched laser was constructed. The shortest pulse width was 409 ns with the repetition rate of 159 kHz, and the maximum output power was 338 mW. To the best of our knowledge, it is the first time that short laser pulses have been generated in a solid state laser at 1.34 mu m using a reflective WS2 SA fabricated by the Langmuir-Blodgett method.
入藏号: WOS:000489101900017
PubMed ID: 31454957
eISSN: 2079-4991
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第 90 条,共 344 条
标题: Secondary electron emission characteristics of Al2O3 coatings prepared by atomic layer deposition
作者: Guo, JJ (Guo, Junjiang); Wang, D (Wang, Dan); Xu, YT (Xu, Yantao); Zhu, XP (Zhu, Xiangping); Wen, KL (Wen, Kaile); Miao, GH (Miao, Guanghui); Cao, WW (Cao, Weiwei); Si, JH (Si, JinHai); Lu, M (Lu, Min); Guo, HT (Guo, Haitao)
来源出版物: AIP ADVANCES 卷: 9 期: 9 文献号: 095303 DOI: 10.1063/1.5113671 出版年: SEP 2019
摘要: Secondary electron emission (SEE) plays a crucial role in the gain performance of devices, such as electron multipliers and microchannel plates (MCPs). Gain performance could be improved by increasing the secondary electron yield (SEY) of device surface. Al2O3 coating is an ideal material for SEE, benefiting from its high SEY. The Al2O3 coating deposited on inner device walls by atomic layer deposition (ALD) can improve the gain performance of devices. In this study, the SEE characteristics of Al2O3 coatings were investigated experimentally. A series of Al2O3 coatings with thicknesses of 1-30 nm were prepared on Si substrate through the ALD method. Then, the SEY of the coatings were quantified as a function of primary electron energy in the range of 100 similar to 1500 eV. Furthermore, an equation describing the true SEY as a function of thickness was established by applying theory of Dionne's SEE model. This work presents potential approach for controlling the SEE level of Al2O3 coatings through thickness adjustment and is crucial for comprehending the SEE of composite materials.
入藏号: WOS:000488516200018
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Dan, Wang                  0000-0002-6337-7177

ISSN: 2158-3226
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第 91 条,共 344 条
标题: Quantitative phase imaging of cells in a flow cytometry arrangement utilizing Michelson interferometer-based off-axis digital holographic microscopy
作者: Min, JW (Min, Junwei); Yao, BL (Yao, Baoli); Trendafilova, V (Trendafilova, Veselina); Ketelhut, S (Ketelhut, Steffi); Kastl, L (Kastl, Lena); Greve, B (Greve, Burkhard); Kemper, B (Kemper, Bjoern)
来源出版物: JOURNAL OF BIOPHOTONICS 卷: 12 期: 9 文献号: e201900085 DOI: 10.1002/jbio.201900085 出版年: SEP 2019
摘要: We combined Michelson-interferometer-based off-axis digital holographic microscopy (DHM) with a common flow cytometry (FCM) arrangement. Utilizing object recognition procedures and holographic autofocusing during the numerical reconstruction of the acquired off-axis holograms, sharply focused quantitative phase images of suspended cells in flow were retrieved without labeling, from which biophysical cellular features of distinct cells, such as cell radius, refractive index and dry mass, can be subsequently retrieved in an automated manner. The performance of the proposed concept was first characterized by investigations on microspheres that were utilized as test standards. Then, we analyzed two types of pancreatic tumor cells with different morphology to further verify the applicability of the proposed method for quantitative live cell imaging. The retrieved biophysical datasets from cells in flow are found in good agreement with results from comparative investigations with previously developed DHM methods under static conditions, which demonstrates the effectiveness and reliability of our approach. Our results contribute to the establishment of DHM in imaging FCM and prospect to broaden the application spectrum of FCM by providing complementary quantitative imaging as well as additional biophysical cell parameters which are not accessible in current high-throughput FCM measurements.
入藏号: WOS:000486778200017
PubMed ID: 31169960
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Kemper, Bjorn                  0000-0003-3693-9397
Trendafilova, Veselina                  0000-0001-8906-899X

ISSN: 1864-063X
eISSN: 1864-0648
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第 92 条,共 344 条
标题: Identification and analysis of vulnerable populations for malaria based on K-prototypes clustering
作者: Li, CL (Li, Chenlu); Wu, XX (Wu, Xiaoxu); Cheng, X (Cheng, Xiao); Fan, C (Fan, Cheng); Li, ZX (Li, Zhixin); Fang, H (Fang, Hui); Shi, CM (Shi, Chunming)
来源出版物: ENVIRONMENTAL RESEARCH 卷: 176 文献号: 108568 DOI: 10.1016/j.envres.2019.108568 出版年: SEP 2019
摘要: Malaria is a serious public health threat in Yunnan Province of China and has been frequently reported in some endemic regions, such as Tengchong County, with high morbidity. It is essential to analyze the characteristics of malaria cases and identify vulnerable populations. Previous studies about vulnerable populations have mostly used a statistical grouping method to count frequence from a single aspect rather than defined clustered groups. Based on descriptive analysis of the temporal variation and demographic structure of the populations with malaria infection, we used a k-prototypes clustering algorithm to cluster vulnerable populations in Tengchong County in three dimensions, according to sex, age, and occupation. The results indicated that a high incidence of malaria occurred mainly in young male farmers and young or middle-aged male migrant workers. Imported cases, low education level, lack of mosquito bite prevention, and risk behaviors contributed to the high malaria incidence in these groups. Double verification ensured the reliability of this method and reasonability of the results. In addition, we highlighted the importance of targeting prevention and control of malaria for vulnerable groups. We provided suggestions of policies and measures to be implemented by regional governments and at household and individual levels for farmers and migrant workers respectively. Using the k-prototypes clustering algorithm, we efficiently identified those populations at greatest risk of malaria infection. Our results may serve as scientific guidance for targeted malaria prevention and control in Yunnan Province.
入藏号: WOS:000483410200032
PubMed ID: 31288195
ISSN: 0013-9351
eISSN: 1096-0953
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第 93 条,共 344 条
标题: Femtosecond laser ablation and photo-induced effects of AS(40)S(60), Ga0.8As39.2S60 and Ga0.8As29.2Sb10S60 chalcogenide glasses
作者: Liu, LT (Liu, Lutao); Zheng, X (Zheng, Xin); Xiao, XS (Xiao, Xusheng); Xu, YT (Xu, Yantao); Cui, XX (Cui, Xiaoxia); Cui, J (Cui, Jian); Guo, CL (Guo, Chunlei); Yang, JJ (Yang, Jianjun); Guo, HT (Guo, Haitao)
来源出版物: OPTICAL MATERIALS EXPRESS 卷: 9 期: 9 页: 3582-3593 DOI: 10.1364/OME.9.003582 出版年: SEP 1 2019
摘要: Laser induced damage thresholds (LIDTs) and photo-induced changes of AS(40)S(60), Ga0.8As39.2S60 and Ga0.8As29.2Sb10S60 chalcogenide glasses are investigated by femtosecond laser of 800nm. AS(40)S(60) glass has the highest LIDT as well as 1452.3 mJ/cm(2), the introduction of small amount of Ga and Sb into glass decreases the LIDTs to 957.1 mJ/cm(2) for Ga0.8As39.2S60 and 705.9 mJ/cm(2) for Ga0.8As29.2Sb10S60, respectively. Microstructure analysis reveals that the decrease of LIDT is tightly related to the decrease of high strength chemical bonds and formation of lower ones in glass matrix. After multi pulses induced damage occurred, the structure of glass matrix became more random and a half of S was replaced by O approximately. The damage mechanism was proposed and it is helpful to develop high LIDT chalcogenide glasses and the photo-induced effects are the basis of waveguide writing in chalcogenide glasses by femtosecond laser. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000484086900002
ISSN: 2159-3930
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第 94 条,共 344 条
标题: Mid-IR Faraday optical filter with an ultra-narrow single transmission peak at 5.33 mu m
作者: Wu, KJ (Wu, Kuijun); Luo, ZJ (Luo, Zhongjie); Feng, YT (Feng, Yutao); Xiong, YH (Xiong, Yuanhui); Yu, GB (Yu, Guangbao); Duan, WM (Duan, Weimin); Li, FQ (Li, Faquan)
来源出版物: APPLIED PHYSICS EXPRESS 卷: 12 期: 9 文献号: 092008 DOI: 10.7567/1882-0786/ab3b3f 出版年: SEP 1 2019
摘要: We present a theoretical and experimental study of a mid-infrared Faraday optical filter (MIFOF) with an ultra-narrow single transmission peak. The typical representative of paramagnetic molecules, gas-phase nitric oxide (NO), is selected as the working material. We focus on the transmission of such a filter operating on a Q(3/2) transition, and its dependence on the strength of the magnetic field. This MIFOF simultaneously achieves a peak transmission of 52%, an equivalent noise bandwidth (ENBW) of 444 MHz, and an out-of-band rejection ratio of 2 x 10(4), for a magnetic field of 17 mT and a NO pressure of 10 mbar. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000483104000001
ISSN: 1882-0778
eISSN: 1882-0786
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第 95 条,共 344 条
标题: All-polarization-maintaining, semiconductor saturable absorbing mirror mode-locked femtosecond Er-doped fiber laser with a gigahertz fundamental repetition rate
作者: Song, JZ (Song, Jiazheng); Hu, XH (Hu, Xiaohong); Wang, HS (Wang, Hushan); Zhang, T (Zhang, Ting); Wang, YS (Wang, Yishan); Liu, YS (Liu, Yuanshan); Zhang, JG (Zhang, Jianguo)
来源出版物: LASER PHYSICS LETTERS 卷: 16 期: 9 文献号: 095102 DOI: 10.1088/1612-202X/ab3421 出版年: SEP 2019
摘要: A passively mode-locked fiber laser with a 1.03 GHz fundamental repetition rate and a low noise performance is demonstrated. The compact and robust laser operates at a central wavelength of 1553.9nm with a 3 dB spectral bandwidth of 7.9 nm and a temporal width of 550 fs. All the fibers and components used in the laser are polarization-maintaining (PM), so the output pulses arc linearly polarized. The degree of polarization of the optical pulses is measured to be 0.9994. The phase noise of the seventh harmonic (7.21 GHz) is measured and a low timing jitter of 11.7 fs is obtained by integrating the phase noise from 30 MHz down to 100 Hz. The noise performance is analyzed in detail, and the methods for further optimizing the timing jitter are also proposed. So far, we know this to be the first-reported low-noise all-PM erbium-doped fiber laser with a gigahertz level pulse repetition rate.
入藏号: WOS:000480295200001
ISSN: 1612-2011
eISSN: 1612-202X
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第 96 条,共 344 条
标题: Ultrabroadband mid-infrared emission from Cr2+-doped infrared transparent chalcogenide glass ceramics embedded with thermally grown ZnS nanorods
作者: Lu, XS (Lu, Xiaosong); Lai, ZQ (Lai, Zhiqiang); Zhang, RN (Zhang, Runan); Guo, HT (Guo, Haitao); Ren, J (Ren, Jing); Strizik, L (Strizik, Lukas); Wagner, T (Wagner, Tomas); Farrell, G (Farrell, Gerald); Wang, PF (Wang, Pengfei)
来源出版物: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY 卷: 39 期: 11 页: 3373-3379 DOI: 10.1016/j.jeurceramsoc.2019.04.048 出版年: SEP 2019
摘要: We report, for the first time to our knowledge, an ultrabroadband mid-infrared (MIR) emission in the range of 1800-2800 nm at room temperature from a Cr2+-doped chalcogenide glass ceramic embedded with pure hexagonal (wurtzite) beta-ZnS nanorods and study the emission-dependent properties on the doping concentration of Cr2+. A new family of chalcogenide glasses based on (100 - x) Ge1.5As2S6.5 -x ZnSe (in mol.%) was prepared by melt-quenching method. The Cr2+: beta-ZnS nanorods of (similar to)150 nm in diameter and (similar to)1 mu m in length were grown in the Cr2+-doped glass after thermal annealing. The compositional variations of glass structures and optical properties were studied. The crystalline phase, morphology of the thermally grown nanorods, and the microscopic elemental distributions were characterized using advanced nanoscale transmission electron microscopy analyses.
入藏号: WOS:000470942800013
ISSN: 0955-2219
eISSN: 1873-619X
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第 97 条,共 344 条
标题: Temporal analysis of Airy beam propagation in photorefractive media
作者: Zhang, MZ (Zhang, M. Z.); Zhang, TY (Zhang, T. Y.); Huo, GW (Huo, G. W.); Hui, ZQ (Hui, Z. Q.); Duan, ZL (Duan, Z. L.); Zha, XW (Zha, X. W.)
来源出版物: COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION 卷: 76 页: 45-50 DOI: 10.1016/j.cnsns.2019.04.011 出版年: SEP 2019
摘要: We theoretically examine the temporal behavior of Airy beams and their interactions in photorefractive medium with the split-step Fourier method. Simulations indicate that Airy beam propagations are effectively controlled by the illumination time. Under saturated nonlinearity, the beam intensity maintains the soliton profile at the output section, and its propagation direction is modulated by the beam amplitude. Moreover, the temporal behavior of Airy beam interactions varies greatly with illumination time, especially for the in-phase case. Breathing solitons and parallel soliton pairs are produced in-phase and outof-phase, respectively. These results are potentially useful in all-optical device applications. (C) 2019 Elsevier B.V. All rights reserved.
入藏号: WOS:000468120500004
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhang, Meizhi         M-8269-2018         0000-0002-7182-0271

ISSN: 1007-5704
eISSN: 1878-7274
________________________________________
第 98 条,共 344 条
标题: Vignetting effect in Fourier ptychographic microscopy
作者: Pan, A (Pan, An); Zuo, C (Zuo, Chao); Xie, YG (Xie, Yuege); Lei, M (Lei, Ming); Yao, BL (Yao, Baoli)
来源出版物: OPTICS AND LASERS IN ENGINEERING 卷: 120 页: 40-48 DOI: 10.1016/j.optlaseng.2019.02.015 出版年: SEP 2019
摘要: In the usual model of Fourier ptychographic microscopy (FPM), the coherent microscopic system is approximated by being taken as linear space-invariant (LSI) with transfer function determined by a complex pupil function of the objective. However, in real experimental conditions, several unexpected "semi-bright and semi-dark" images with strong vignetting effect can be observed when the sample is illuminated by the LEDs within the "transition zone" between bright field and dark field. These imperfect images, apparently, are not coincident with the LSI model and could deteriorate the reconstruction quality severely. Herein, we investigate the cause and the impact of model misfit based on ray-based and rigorous wave optics-based analysis. Our analysis shows that for a practical FPM microscope with a low magnification objective and a large field-of-view (FOV), the LSI model breaks down as a result of diffraction at other stops or apertures associated with different lens elements. A modified version of the linear space-variant (LSV) model is derived for quantitative analysis. The spectrum of the object will be modulated unexpectedly by a quadratic phase term relatively if assuming the shape of pupil function is invariable. Two countermeasures are also presented and experimentally verified to bypass or alleviate the vignetting-induced reconstruction artifacts. An adaptive update order and initial guess strategy is proposed and demonstrated for better reconstructions. Our work gives a deeper insight into the vignetting effect on wide-FOV imaging and provides a useful guide for easily achieving improved FPM reconstructions that bypass the adverse effect.
入藏号: WOS:000468250700006
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zuo, Chao         N-2317-2019         0000-0002-1461-0032

ISSN: 0143-8166
eISSN: 1873-0302
________________________________________
第 99 条,共 344 条
标题: Local difference-based active contour model for medical image segmentation and bias correction
作者: Niu, YF (Niu, Yuefeng); Cao, JZ (Cao, Jianzhong)
来源出版物: IET IMAGE PROCESSING 卷: 13 期: 10 页: 1755-1762 DOI: 10.1049/iet-ipr.2018.5230 出版年: AUG 22 2019
摘要: This study proposes a local bias field and difference estimation (LBDE) model for medical image segmentation and bias field correction. Firstly, the LBDE model uses a linear combination of a given set of smooth orthogonal basis functions, which is called Chebyshev polynomial, to estimate the bias field. Then, a clustering criterion function is defined by considering the difference between the measured image and approximated image in a small region. By applying this difference in the local region, the LBDE model can obtain accurate segmentation results and estimation of the bias field. Finally, the energy functional is incorporated into a level set formulation with a regularisation term, and it is minimised via the level set evolution process. The LBDE model first appears as a two-phase model and then extends to the multi-phase one. Extensive experiments on medical images demonstrate that the LBDE model achieves more precise segmentation results in terms of Jaccard similarity and dice similarity coefficient than the comparative models. Therefore the proposed model can increase the segmentation accuracy and robustness to noise.
入藏号: WOS:000484975000018
ISSN: 1751-9659
eISSN: 1751-9667
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第 100 条,共 344 条
标题: A novel bowl-shaped microchannel plate with high electron collection efficiency and good time performance
作者: Chen, P (Chen, Ping); Tian, JS (Tian, Jinshou); Yuan, XH (Yuan, Xiaohui); Wen, WL (Wen, Wenlong); Wang, X (Wang, Xing); Guo, LH (Guo, Lehui); Liu, HL (Liu, Hulin); Wei, YL (Wei, Yonglin); Pei, CQ (Pei, Chengquan); He, K (He, Kai); Lu, Y (Lu, Yu); Sai, XF (Sai, Xiaofeng); Wu, WQ (Wu, Wenqing); Deng, YQ (Deng, Yanqing); Zhao, X (Zhao, Xu)
来源出版物: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 卷: 936 页: 534-536 DOI:10.1016/j.nima.2018.11.145 出版年: AUG 21 2019
摘要: Owing to the severe loss of photoelectrons striking at the input electrode of conventional microchannel plate (MCP), photoelectron collection efficiency (CE) of devices based on traditional MCP fluctuates around the MCP open area ratio and cannot make a breakthrough. Photoelectron back scattering from the MCP surface also causes late pulses smearing timing and spatial performance. In this work, a novel bowl-shaped MCP with an open area ratio higher than 90% whose input electrode is coated by a thin film with high secondary electron emission yield (SEY) is proposed as an effective approach to improve CE and suppress late pulses. A three-dimensional MCP-PMT model is developed in CST Studio Suite to evaluate CE and time performance of the bowl-shaped MCP, and compared with the traditional one. Results show that CE of the PMT based on the bowl-shaped MCP is nearly 100% and the delayed pulse is less than 2%. This indicates that good temporal and spatial resolution can be achieved with the bowl-shaped MCP.
入藏号: WOS:000471828100201
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
yuan, xiaohui         O-4622-2015         0000-0001-8924-4682

ISSN: 0168-9002
eISSN: 1872-9576

第 101 条,共 344 条
标题: Simulation of microchannel plate photomultiplier tube in high magnetic fields
作者: Chen, P (Chen, Ping); Yuan, XH (Yuan, Xiaohui); Tian, JS (Tian, Jinshou); Wang, X (Wang, Xing); Wen, WL (Wen, Wenlong); Guo, LH (Guo, Lehui); Tian, LP (Tian, Liping); Lu, Y (Lu, Yu); Liu, HL (Liu, Hulin); Wei, YL (Wei, Yonglin); Pei, CQ (Pei, Chengquan); He, K (He, Kai); Sai, XF (Sai, Xiaofeng); Wei, WQ (Wei, Wenqing); Deng, YQ (Deng, Yanqing); Zhao, X (Zhao, Xu)
来源出版物: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 卷: 936 页: 580-582 DOI:10.1016/j.nima.2018.10.088 出版年: AUG 21 2019
摘要: The microchannel plate photomultiplier tube (MCP-PMT) used in high energy physics experiments usually needs to be able to operate in strong magnetic fields. In this paper, a 3D MCP-PMT model is developed in CST studio suite to study the magnetic field up to 5 T effect on the photoelectrons traveling from the photocathode to the MCP. Results predict that a growing number of photoelectrons strike back to the photocathode with enhancing magnetic field, which not only decreases electron collection efficiency and gain, but also impairs the photocathode lifetime.
入藏号: WOS:000471828100220
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
yuan, xiaohui         O-4622-2015         0000-0001-8924-4682

ISSN: 0168-9002
eISSN: 1872-9576
________________________________________
第 102 条,共 344 条
标题: Optical design of X-ray focusing telescope
作者: Qiang, PF (Qiang Peng-Fei); Sheng, LZ (Sheng Li-Zhi); Li, LS (Li Lin-Sen); Yan, YQ (Yan Yong-Qing); Liu, Z (Liu Zhe); Zhou, XH (Zhou Xiao-Hong)
来源出版物: ACTA PHYSICA SINICA 卷: 68 期: 16 文献号: 160702 DOI: 10.7498/aps.68.20190709 出版年: AUG 20 2019
摘要: X-ray focusing telescope is one of the most important equipment for X-ray space observation, which is designed based on the grazing incidence principle. The purpose of x-ray observation is to detect the black holes of various sizes in outer space, and the data obtained by X-ray telescope conduces to investigating the basic physical law under the condition of extreme gravity and magnetic field, In this article, multi-layer telescope is designed to satisfy the demand for enhanced X-ray timing and polarimetry mission. in which the telescope is designed based on Wolter-I telescope. The Monte Carlo method and power spectral density are used when the relationship between mirror profile and roughness with angular resolution is investigated. We analyze the relationship between angular resolution and mirror profile, and the result shows that the higher mirror profile possesses higher angular resolution. When the root mean square(RMS) of mirror profile is 0.04 mu m, PV is 0.2 mu m and roughness is 0.4 nm, the mirror angular resolution is 6.3 '' and it will change to 30.6 '' when the RMS of mirror profile is 0.2 mu m, PV is 1 mu m and roughness is 0.4 nm. The angular resolution out of focus is also investigated in this article, and the more defocusing amount gives rise to the worse angular resolution because defocusing spot will be larger than that of focal plane. So the maximum defocusing amount of 5 mm is required when the focal plane detector is installed. The relationship between effective area with film structure and layers number is also investigated. The film with Au mixed with C has a higher reflectivity than the film with only Au, because the mixed film will generate an interference effect and enhance the intensity of reflecting X-ray. When the telescope layers increase, the effective area and telescope weight are both improved, the requirement for effective area of satellite can be satisfied when the number of nesting layers is 45. However, when the number of nesting layers further increase, the effective area will be improved with a low speed, but the weight of telescope will increase with a high speed. The field of view of this telescope is 16', which is more than the required value of 12'. Finally, the X-ray focusing telescope with 5.25 m focal length, 45 nesting layers, effective area 842 cm(2) at 2 keV, 563 cm(2) at 6 keV is obtained.
入藏号: WOS:000483384000004
ISSN: 1000-3290
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第 103 条,共 344 条
标题: Photorefractive effect of low-temperature-grown aluminum gallium arsenide
作者: Zhong, ZY (Zhong Zi-Yuan); He, K (He Kai); Yuan, Y (Yuan Yun); Wang, T (Wang Tao); Gao, GL (Gao Gui-Long); Yan, X (Yan Xin); Li, SH (Li Shao-Hui); Yin, F (Yin Fei); Tian, JS (Tian Jin-Shou)
来源出版物: ACTA PHYSICA SINICA 卷: 68 期: 16 文献号: 167801 DOI: 10.7498/aps.68.20190459 出版年: AUG 20 2019
摘要: The ternary compound aluminum gallium arsenide is an important material that can be used in all-optical solid-state ultrafast diagnostic technology. The low-temperature-epitaxially-grown AlGaAs (LT-AlGaAs) not only has the characteristics of ultra-short carrier lifetime of low-temperature-grown gallium arsenide (LT-GaAs), but also possesses the advantage of adjustability of band gap, which will provide great flexibility for the design of ultra-fast diagnostic systems. We use low-temperature epitaxial growth technology to grow AlGaAs on a GaAs substrate. The low-temperature-grown AlGaAs can effectively absorb 400 nm pump light to generate excess carrier. Therefore, we use a femtosecond laser with a wavelength of 800 nm and a pulse width of 200 fs as a light source to generate 400-nm pump light after passing through the BBO crystal, and 800 nm light without frequency doubling as the probe light. Using such a light source, we build a pump probe experimental platform to test the LT-AlGaAs. We normalize the experimental results and deconvolute it with the normalized laser pulses to obtain the response function of the semiconductor to the pump light. Therefore, we know that the nonequilibrium carrier relaxation time is less than 300 fs, and the nonequilibrium carrier recombination time is 2.08 ps. Due to the special passivation process, the effect of surface recombination on the carrier decay process is greatly reduced. The As clusters introduced by low-temperature epitaxial growth form deep level defects are the main factor for accelerating carrier recombination. In order to understand the complex process of photogenerated nonequilibrium carriers in depth, we use the indirect recombination theory of single recombination center to calculate the carrier recombination process, and establish an LT-AlGaAs carrier evolution model. Thus we obtain the key physical parameter related to the recombination rate, which is the carrier trapping area. We also use a theoretical model of carrier-regulated refractive index to calculate the effect of carrier concentration on the amount of change in refractive index. Combining our AlGaAs carrier evolution model, we simulate the refractive index change process of LT-AlGaAs after being illuminated by pump light. The simulation results are in good agreement with the experimental results. The method can be used for the quantitative analysis of carrier evolution characteristics of semiconductor materials, and it can conduce to the optimization and improvement of ultra-fast response semiconductor materials.
入藏号: WOS:000483384000028
ISSN: 1000-3290
________________________________________
第 104 条,共 344 条
标题: Easy method to measure the packaging-induced stress of a semiconductor laser diode by lasing wavelength shifting
作者: Zhang, HY (Zhang, Hongyou); Fu, TW (Fu, Tuanwei); Zah, CE (Zah, Chung-En); Liu, XS (Liu, Xingsheng)
来源出版物: APPLIED OPTICS 卷: 58 期: 24 页: 6672-6677 DOI: 10.1364/AO.58.006672 出版年: AUG 20 2019
摘要: In this paper, the packaging-induced stresses are theoretically calculated by modeling multilayered structures for different packaging structures. We report a method to measure the packaging-induced stress of a laser diode array (LDA) by comparing the emission wavelength of the single emitter located in the middle of a laser bar before and after packaging. The wavelength is tested under a low duty cycle (50 mu s/10 Hz, DC 0.05%) to eliminate the thermal effect to wavelength shifting. Experimental calculation results for the packaging-induced stress of LDAs are in good agreement with the theoretical calculations and simulation results. For a GaAs laser bar, we find the packaging stresses are compression stresses, which make the emission wavelength blue-shift in terms of 1.09 x 10(-2) nm/MPa. We propose a mapping of packaging-induced stress distribution in laser bars on a microscopic scale by considering the emission spectra of each emitter in a laser bar. Compared to single-emitter resolved photo-current or micro-photoluminescence measurements, as proposed by other authors, we offer a much easier tool to test and map the distribution of packaging-induced stress in laser bars. (C) 2019 Optical Society of America
入藏号: WOS:000482095100026
PubMed ID: 31503599
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ZHANG, Hongyou                  0000-0001-5776-0025

ISSN: 1559-128X
eISSN: 2155-3165
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第 105 条,共 344 条
标题: Atomic-Scale Simulation of the Contact Behavior and Mechanism of the SWNT-AgNW Heterostructure
作者: Cui, JL (Cui, Jianlei); Zhang, JW (Zhang, Jianwei); Wang, XW (Wang, Xuewen); Theogene, B (Theogene, Barayavuga); Wang, WJ (Wang, Wenjun); Tohmyoh, H (Tohmyoh, Hironori); He, XQ (He, Xiaoqiao); Mei, XS (Mei, Xuesong)
来源出版物: JOURNAL OF PHYSICAL CHEMISTRY C 卷: 123 期: 32 页: 19693-19703 DOI: 10.1021/acs.jpcc.9b05181 出版年: AUG 15 2019
摘要: We investigated the interfacial contact behavior of the side-to-side biaxial heterostructure between carbon nanotubes and silver nanowires on an atomic scale. The nanotubes can move along the nanowire periphery and keep pace with the silver nanowires, and in some cases, a collapse occurs and quickly creates a domino effect that readily forms the bilayer graphene-like structures with a face-to-face pi-pi stacking effect that adhere firmly to the nanowire surface. When the diameter of an armchair nanotube is very large, the bilayer graphene-like structure that has been formed can scroll onto the nanowire periphery and wrap around the nanowire to form a core/shell hybrid structure that will eventually be transformed into a double-walled carbon nanotube structure. In other circumstances that are affected by factors such as temperature and the nanotube structure, the carbon nanotube does not easily collapse; instead, it retains its intrinsic circular form. The mechanism for interfacial contact behavior reveals that the van der Waals interactions play an important role in the entire process. The effects of the interfacial contact behavior and the final atomic configuration may provide valuable theoretical guidance for designing and fabricating hybrid structures with broad potential applications, such as nanoelectronic devices and functional composite materials.
入藏号: WOS:000481568900049
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
WANG, Xuewen                  0000-0003-2075-7759
Cui, Jianlei                  0000-0002-5760-509X

ISSN: 1932-7447
eISSN: 1932-7455
________________________________________
第 106 条,共 344 条
标题: Optimization investigation for high-power 1034 nm all-fiber narrowband Yb-doped superfluorescent source
作者: Wu, P (Wu, Peng); Zhao, BY (Zhao, Baoyin); Zhao, W (Zhao, Wei); Li, Z (Li, Zhe); Gao, W (Gao, Wei); Ju, P (Ju, Pei); Li, G (Li, Gang); Gao, Q (Gao, Qi); Wang, YS (Wang, Yishan)
来源出版物: OPTICS COMMUNICATIONS 卷: 445 页: 187-192 DOI: 10.1016/j.optcom.2019.04.033 出版年: AUG 15 2019
摘要: An optimization for all-fiber narrowband Yb-doped superfluorescent source with a central wavelength shorter than 1040 nm is conducted theoretically and then verified experimentally using steady-state rate equations. Theoretical investigation indicates that with the increase in fiber length, signal power presents one peak value, but the ratio of signal power to output power is decreasing monotonously. Moreover, a filter with high extinction ratio and a gain fiber with high absorption coefficient can have gain suppression on a long wavelength. One all-fiber superfluorescent source is built experimentally on the basis of the theoretically optimized parameters. The source achieves an output power of 214.64 W with a central wavelength of 1034.18 nm and signal-noise ratio of 30 dB. The output power of the source can have further power scaling with considerable available pump power.
入藏号: WOS:000468114800030
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 107 条,共 344 条
标题: Discrete image recovery via stochastic resonance in optically induced photonic lattices
作者: Zhang, YB (Zhang, Yongbin); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu)
来源出版物: SCIENTIFIC REPORTS 卷: 9 文献号: 11815 DOI: 10.1038/s41598-019-48313-y 出版年: AUG 14 2019
摘要: We demonstrate numerically the discrete image recovery via stochastic resonance in optically induced photonic lattices. The underlying signals are regularly reinforced at the expense of scattering noise with the interplay of the periodic potentials and the self-focusing nonlinearity. We founded that the energy redistribution tends to be periodic and the signal reinforcement is promoted with the help of periodic potentials. The lattice intensity levels, applied voltages, and correlation lengths are important parameters to influence the recovery effects. The dynamic nonlinear evolution including intensity and power spectrum is modeled according to the two-dimensional quasi-particle motion model. Our results suggest a potential technology to detect the noisy images.
入藏号: WOS:000480678100014
PubMed ID: 31413338
ISSN: 2045-2322
________________________________________
第 108 条,共 344 条
标题: Graphene Oxide Waveguide and Micro-Ring Resonator Polarizers
作者: Wu, JY (Wu, Jiayang); Yang, YY (Yang, Yunyi); Qu, Y (Qu, Yang); Xu, XY (Xu, Xingyuan); Liang, Y (Liang, Yao); Chu, ST (Chu, Sai Tak); Little, BE (Little, Brent E.); Morandotti, R (Morandotti, Roberto); Jia, BH (Jia, Baohua); Moss, DJ (Moss, David J.)
来源出版物: LASER & PHOTONICS REVIEWS 卷: 13 期: 9 文献号: 1900056 DOI: 10.1002/lpor.201900056 提前访问日期: AUG 2019 出版年: SEP 2019
摘要: Integrated waveguide polarizers and polarization-selective micro-ring resonators (MRRs) incorporated with graphene oxide (GO) films are experimentally demonstrated. CMOS-compatible doped silica waveguides and MRRs with both uniformly coated and patterned GO films are fabricated based on a large-area, transfer-free, layer-by-layer GO coating method that yields precise control of the film thickness. Photolithography and lift-off processes are used to achieve photolithographic patterning of GO films with precise control of the placement and coating length. Detailed measurements are performed to characterize the performance of the devices versus GO film thickness and coating length as a function of polarization, wavelength and power. A high polarization dependent loss of approximate to 53.8 dB is achieved for the waveguide coated with 2-mm-long patterned GO films. It is found that intrinsic film material loss anisotropy dominates the performance for less than 20 layers whereas polarization-dependent mode overlap dominates for thicker layers. For the MRRs, the GO coating length is reduced to 50 mu m, yielding a approximate to 8.3 dB polarization extinction ratio between transverse electric (TE) and transverse magnetic (TM) resonances. These results offer interesting physical insights and trends of the layered GO films and demonstrate the effectiveness of introducing GO films into photonic-integrated devices to realize high-performance polarization selective components.
入藏号: WOS:000481369500001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
Wu, Jiayang                  0000-0003-1115-610X

ISSN: 1863-8880
eISSN: 1863-8899
________________________________________
第 109 条,共 344 条
标题: Ultrafast dynamics of three types of simultaneous shockwaves and filament attenuation in femtosecond laser multi-pulse ablation of PMMA
作者: Wang, GY (Wang, Guoyan); Jiang, L (Jiang, Lan); Sun, JY (Sun, Jingya); Hu, J (Hu, Jie); Wang, QS (Wang, Qingsong); Li, M (Li, Ming); Lu, YF (Lu, Yongfeng)
来源出版物: CHINESE OPTICS LETTERS 卷: 17 期: 8 文献号: 081405 DOI: 10.3788/COL201917.081405 出版年: AUG 10 2019
摘要: Cylindrical shockwaves inside polymethyl methacrylate (PMMA) generated simultaneously with two hemispherical shockwaves induced by a femtosecond Gaussian beam laser were investigated using an ultrafast pump-probe imaging technique. The evolutions of these three shockwaves with probe delay and incident pulse number have been systematically analyzed. The plasma intensity and filament length in the center of cylindrical shockwave both decayed with pulse number. Moreover, the self-focused filament moved downstream towards the output surface with an increased pulse number. The experimental results and mechanism illustrated that energy deposition was suppressed by a degraded nonlinear effect due to a pre-ablated structure in multi-pulse irradiation.
入藏号: WOS:000482217600012
ISSN: 1671-7694
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第 110 条,共 344 条
标题: Multi-view object topography measurement with optical sectioning structured illumination microscopy
作者: Ren, FF (Ren, Feifei); Wang, ZJ (Wang, Zhaojun); Qian, J (Qian, Jia); Liang, YS (Liang, Yansheng); Dang, SP (Dang, Shipei); Cai, YN (Cai, Yanan); Bianco, PR (Bianco, Piero R.); Yao, BL (Yao, Baoli); Lei, M (Lei, Ming)
来源出版物: APPLIED OPTICS 卷: 58 期: 23 页: 6288-6294 DOI: 10.1364/AO.58.006288 出版年: AUG 10 2019
摘要: Various optical instruments have been developed for three-dimensional (3D) surface topography, including the white light interference, reflectance confocal microscopes, and digital holographic microscopes, etc. However, the steep local slope of objects may cause the light to be reflected in a way that it will not be captured by the objective lens because of the finite collection angle of the objective. To solve this "shadow problem," we report a method to enlarge the collection angle range of optical sectioning structured illumination microscopy by capturing sectioned images of the objects from multiple angle of views. We develop a multi-view image fusion algorithm to reconstruct a single 3D image. Using this method, we detect previously invisible details whose slopes are beyond the collection angle of the objective. The proposed approach is useful for height map measurement and quantitative analyses in a variety of fields, such as biology, materials science, microelectronics, etc. (C) 2019 Optical Society of America
入藏号: WOS:000480414100013
PubMed ID: 31503772
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Liang, Yansheng                  0000-0002-3561-1317

ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 111 条,共 344 条
标题: Instability transverse mode phase transition of fiber oscillator for extreme power lasers
作者: Gao, W (Gao, Wei); Zhao, BY (Zhao, Baoyin); Fan, WH (Fan, Wenhui); Ju, P (Ju, Pei); Zhang, YP (Zhang, Yanpeng); Li, G (Li, Gang); Gao, Q (Gao, Qi); Li, Z (Li, Zhe)
来源出版物: OPTICS EXPRESS 卷: 27 期: 16 页: 22393-22407 DOI: 10.1364/OE.27.022393 出版年: AUG 5 2019
摘要: High-power fiber lasers have been widely explored in engineering and science, and improving the beam quality restricted by transverse mode instability (TMI) is waiting to be solved for extra high-power applications. Here, we theoretically propose a phase transition model for understanding TMI in a fiber oscillator. A general dynamics model describing TMI is established by modifying the heat equation, and then a special dynamics model of a two-mode fiber (TMF) oscillator is obtained by applying this general dynamics model to TMF oscillator case. Theoretical analysis shows that there is a reversible phase transition point in this TMF oscillator model, which can well explain the sudden and reversible change of TMI. Based on linear stability analysis near the phase transition point, an analytical threshold formula of TMI is given to calculate the TMI threshold in the TMF oscillator. The calculated results are consistent with the reported experimental results. Furthermore, the relationship between the TMI threshold and several parameters was also discussed in detail such as laser wavelength, pump wavelength, core radius, cladding radius, etc. This theoretical model will be useful to understand and suppress the TMI in fiber oscillators. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000478790400057
PubMed ID: 31510534
ISSN: 1094-4087
________________________________________
第 112 条,共 344 条
标题: Grafted optical vortex with controllable orbital angular momentum distribution
作者: Zhang, H (Zhang, Hao); Li, XZ (Li, Xinzhong); Ma, HX (Ma, Haixiang); Tang, MM (Tang, Miaomiao); Li, HH (Li, Hehe); Tang, J (Tang, Jie); Cai, YJ (Cai, Yangjian)
来源出版物: OPTICS EXPRESS 卷: 27 期: 16 页: 22930-22938 DOI: 10.1364/OE.27.022930 出版年: AUG 5 2019
摘要: In an optical vortex (OV) field, the orbital angular momentum (OAM) distribution strongly depends on the intensity, which results in difficulty in OAM independent modulation. To overcome this limitation, we propose a grafted optical vortex (GOV) via spiral phase reconstruction of two or more OVs with different topological charges (TCs). To remain the annular shape of the GOV's intensity, the Dirac delta-function is employed to restrict the energy in a ring. Theoretical analysis and manipulation experiments of polystyrene microspheres show that the magnitude and direction of the GOV's local OAM are controllable by modulating the grafted TCs while the intensity remains constant. The results of this work provide an ingenious method to control the local tangential force on the light ring, which will promote potential applications in optical trapping and rotating micro-particles. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000478790400099
PubMed ID: 31510577
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xinzhong         P-7966-2018         0000-0002-6426-4043
Ma, Haixiang                  0000-0001-9422-9372
Zhang, Hao                  0000-0001-6514-9090

ISSN: 1094-4087
________________________________________
第 113 条,共 344 条
标题: Cylindrically Focused Nonablative Femtosecond Laser Processing of Long-Range Uniform Periodic Surface Structures with Tunable Diffraction Efficiency
作者: Huang, J (Huang, Ji); Jiang, L (Jiang, Lan); Li, XW (Li, Xiaowei); Wei, QS (Wei, Qunshuo); Wang, ZP (Wang, Zhipeng); Li, BH (Li, Bohong); Huang, LL (Huang, Lingling); Wang, AD (Wang, Andong); Wang, Z (Wang, Zhi); Li, M (Li, Ming); Qu, LT (Qu, Liangti); Lu, YF (Lu, Yongfeng)
来源出版物: ADVANCED OPTICAL MATERIALS 卷: 7 期: 20 文献号: 1900706 DOI: 10.1002/adom.201900706 提前访问日期: AUG 2019 出版年: OCT 2019
摘要: Periodic surface structures are core components for controlling the dispersion and steering characteristics of light. Here, a mask-free approach using nonablative femtosecond laser processing is proposed and demonstrated to fabricate extremely long-range uniform periodic surface structures on silicon with tunable diffraction efficiency. First, a cylindrically focused femtosecond laser scans over silicon substrates to efficiently produce large-area periodic modified stripes in a nonablation regime. Second, the modified stripes act as fine etch stops to generate the desired structures on sample surfaces during the subsequent chemical etching process. The structures produced by the method achieve optimal long-range uniformity compared to the reported laser-induced periodic surface structures, which possess a minimum divergence of structure orientation angles of <5 degrees. In addition, the optical characteristics of the prepared structures are measured experimentally. Distinguishable polychromatic diffraction patterns can be clearly observed by broadband light irradiation. Significantly, the chemical etching process endues the structures with ingenious morphology controllability, so that the diffraction efficiency of the incident light can be flexibly tuned, which exhibits a near-linear function of the etching duration. Such morphology-controllable periodic surface structures may facilitate applications in broad fields, such as optical communications and optical sensors.
入藏号: WOS:000478972600001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
, Xiaowei                  0000-0003-1707-4957

ISSN: 2195-1071
________________________________________
第 114 条,共 344 条
标题: Single Space Object Image Denoising and Super-Resolution Reconstructing Using Deep Convolutional Networks
作者: Feng, XB (Feng, Xubin); Su, XQ (Su, Xiuqin); Shen, JG (Shen, Junge); Jin, HM (Jin, Humin)
来源出版物: REMOTE SENSING 卷: 11 期: 16 文献号: 1910 DOI: 10.3390/rs11161910 出版年: AUG 2019
摘要: Space object recognition is the basis of space attack and defense confrontation. High-quality space object images are very important for space object recognition. Because of the large number of cosmic rays in the space environment and the inadequacy of optical lenses and detectors on satellites to support high-resolution imaging, most of the images obtained are blurred and contain a lot of cosmic-ray noise. So, denoising methods and super-resolution methods are two effective ways to reconstruct high-quality space object images. However, most super-resolution methods could only reconstruct the lost details of low spatial resolution images, but could not remove noise. On the other hand, most denoising methods especially cosmic-ray denoising methods could not reconstruct high-resolution details. So in this paper, a deep convolutional neural network (CNN)-based single space object image denoising and super-resolution reconstruction method is presented. The noise is removed and the lost details of the low spatial resolution image are well reconstructed based on one very deep CNN-based network, which combines global residual learning and local residual learning. Based on a dataset of satellite images, experimental results demonstrate the feasibility of our proposed method in enhancing the spatial resolution and removing the noise of the space objects images.
入藏号: WOS:000484387600073
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Feng, Xubin                  0000-0003-4348-7632

eISSN: 2072-4292
________________________________________
第 115 条,共 344 条
标题: Retrieval of Hydrothermal CH4 Based on Interference Spectroscopy and PLS Methods
作者: Liu, QS (Liu Qing-song); Hu, BL (Hu Bing-liang); Tang, YH (Tang Yuan-he); Yu, T (Yu Tao); Wang, XJ (Wang Xue-ji); Liu, YZ (Liu Yong-zheng); Yang, P (Yang Peng); Wang, HX (Wang Hao-xuan)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS 卷: 39 期: 8 页: 2415-2420 DOI: 10.3964/j.issn.1000-0593(2019)08-2415-06 出版年: AUG 2019
摘要: The methane (CH4) gas released by hydrothermal enters into the ocean and atmosphere successively by diffusing and causes inestimable effect on earth in physics, chemistry and biology. The principle and environment effect of abyssal hydrothermal still require further study because limited information is available about dissolved methane. In our previous work, we propose an optical passive imaging interference system (OPIIS) for the real-time detection and long-term observation of hydrothermal methane's concentration, temperature, and pressure. To accurately, stably, and rapidly obtain the information of hydro thermal methane from OPIIS's interferogram, this paper processes OPIIS' s data by combining interference spectra and partial least squares (PLS) algorithm. We built three single-dependent variable models between methane radiance spectra and gas concentration, temperature and pressure, respectively. Then we can establish the PLS prediction model between interference fringes indirectly on the basis of relationship between interference fringes and radiance spectra, which can improve the capacity of resisting disturbance and stability of prediction models in practical application. On the basis of Lorentz profile, we build the deep ocean gas emission model different from atmosphere emission and obtain the synthetic methane radiance spectrum database at any concentration, temperature and pressure by using the methane spectral parameters from HITRAN2016 molecular spectroscopy database. The six spectral lines of methane in the range of 1. 64 similar to 1. 66 mu m are selected for the PLS regression model between methane radiance spectra and gas concentration, temperature and pressure. Furthermore, this paper analyzes the contribution of number of training samples, interval of training samples and number of principal components to the improvement of the comprehensive performance of regression model. The 96 groups of concentration, temperature and pressure regression model are built by using different groups, intervals and principal components, and those regression models are cross-validated using 25 groups of prediction samples. The comparison results of those regression models' root mean square error of prediction (RMSEP) and coefficient of determination (R-2) indicate that the change of single factors such as the number of training samples, the interval of training samples and the number of principal components can not improve the prediction model' s comprehensive performance about prediction accuracy, stability, application scope and computation. Finally, the optimized model with balanced performance is determined with concentration, temperature and pressure application ranges at 5 similar to 375 mmol . L-1, 580 similar to 678 K, 10 similar to 34. 5 MPa, training samples of concentration, temperature and pressure are 50 groups, 25 groups, 25 groups, intervals at 5 mmol . L-1, 2 K, 0. 5 MPa, principal components are 2, 2, 5. The RMSEPs of concentration, temperature and pressure are 3. 082X 10(-1), 0. 977 0, 5. 052 X 10(-3), and Res are 0. 999 9, 0. 998 9, 0. 999 9, respectively. The prediction errors of concentration, temperature and pressure are +/- 1. 21 X 10(-7), +/- 3. 63 X 10(-3), +/- 9. 49 X 10(-4), and the corresponding precisions are +/- 45. 4 mmol . L-1, +/- 2. 5 K, +/- 3. 3 X 10(-2) MPa.
The results indicate that this retrieval algorithm can accurately, stably, and rapidly obtain concentration, temperature and pressure of hydrothermal methane.
入藏号: WOS:000483420700016
ISSN: 1000-0593
________________________________________
第 116 条,共 344 条
标题: Sequential Combination of Femtosecond Laser Ablation and Induced Micro/Nano Structures for Marking Units with High-Recognition-Rate
作者: Sun, XY (Sun, Xiaoyun); Wang, WJ (Wang, Wenjun); Mei, XS (Mei, Xuesong); Pan, AF (Pan, Aifei); Zhang, J (Zhang, Ju); Li, M (Li, Ming); Li, X (Li, Xun)
来源出版物: ADVANCED ENGINEERING MATERIALS 卷: 21 期: 8 文献号: 1900350 DOI: 10.1002/adem.201900350 出版年: AUG 2019
摘要: This study reported the sequential combination of femtosecond laser ablation and induced micro/nano structures on the titanium alloy and nickel-based alloy for laser marking. The preliminary optimization of processing parameters of laser ablation for the marking units is first carried out. The repetition frequency of 50 kHz, the pulse energy of 150 mu J, the scanning speed from 60 to 80 mm s(-1), and the groove spacing from 10 to 20 mu m are selected as the best processing parameters. Laser-induced micro/nano structures with anti-reflective properties are formed in the primary laser marking zone, which resulted in further improvement in the recognition rate of the markings. For the two alloys, the recognition rate of combined markings is higher than that of primary markings, because the reflectance of the combined markings is lower than that of the primary markings in the spectrum ranging from 380 to 1000 nm. X-ray diffraction analysis showed that the phase constitution of the processed surface is basically consistent with that of the substrate. Moreover, the cracks and re-cast are not observed under metallographic analysis. Therefore, the sequential combination of femtosecond laser ablation and induced micro/nano structures provides a new marking technology with high recognition rate and quality.
入藏号: WOS:000481868900026
ISSN: 1438-1656
eISSN: 1527-2648
________________________________________
第 117 条,共 344 条
标题: A Characteristic Extraction Algorithm Based on Blocking Star Images
作者: Du, Y (Du, Yun); Wen, DS (Wen, Desheng); Liu, GZ (Liu, Guizhong); Qiu, S (Qiu, Shi); Li, N (Li, Ni)
来源出版物: INTERNATIONAL JOURNAL OF PATTERN RECOGNITION AND ARTIFICIAL INTELLIGENCE 卷: 33 期: 9 文献号: 1954028 DOI: 10.1142/S0218001419540284 出版年: AUG 2019
摘要: The star images obtained through the CCD camera can visually display the star structure. In order to get the wide starry image, we need to extract the characteristics of star images to achieve the star image stitching. In the star images, star points, whose characteristics are limited, are easily influenced by noise and are also difficult to extract. The number of stars is too large to stitch accurately. Thus, we propose a stitching algorithm based on blocking star images. First, we establish the maximum intensity projection model based on time sequence to locate the star points accurately. Then, according to the relative positions of star points, the block model is introduced to realize the establishment of the characteristics. Finally, the star image stitching is achieved from the perspective of the characteristic similarity. The experiments illustrate that CM (combination measure) reaches 0.87, and the proposed algorithm has better anti-noise performance and robustness.
入藏号: WOS:000480299300005
ISSN: 0218-0014
eISSN: 1793-6381
________________________________________
第 118 条,共 344 条
标题: Enantioselective optical trapping of chiral nanoparticles by tightly focused vector beams
作者: Li, MM (Li, Manman); Yan, SH (Yan, Shaohui); Zhang, YN (Zhang, Yanan); Zhang, P (Zhang, Peng); Yao, BL (Yao, Baoli)
来源出版物: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 卷: 36 期: 8 页: 2099-2105 DOI: 10.1364/JOSAB.36.002099 出版年: AUG 1 2019
摘要: Two enantiomers (mirror images) can show drastically different behaviors, resulting in the enantiomers' identification and separation being in high demand in biomedical research and industry. Here, we introduce an optical approach in which, by using a tightly focused vector beam with radially varied polarizations, we realize the selective trapping of both enantiomeric forms. Numerical results show that such a focused field exhibits bifocal spot intensity distribution and can simultaneously stably trap one enantiomer in one focal spot and the other enantiomer in the other spot in three dimensions, achieving an effective separation of the chiral entities. The trapping distance and position of the enantiomeric pairs can be changed by separately varying the magnitude and sign of the polarization topological charge of the vector beam. And the difference in trapping potentials of the particles with different chirality provides a further identification of the chirality. Our theory indicates that the enantiomers' identification and separation can be mediated by the same incident beam, providing a possible route to detect, separate, and manipulate chiral objects at nanometer scales. (C) 2019 Optical Society of America
入藏号: WOS:000478057200037
ISSN: 0740-3224
eISSN: 1520-8540
________________________________________
第 119 条,共 344 条
标题: Gaussian-like and flat-top solitons of a oms with spatially modulated epulsive interactions
作者: Zeng, LW (Zeng, Liangwei); Leng, JH (Leng, Jianhua)
来源出版物: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 卷: 36 期: 8 页: 2278-2284 DOI: 10.1364/JOSAB.36.002278 出版年: AUG 1 2019
摘要: Solitons, nonlinear particle-like excitations with inalterable properties (amplitude, shape, and velocity) as they propagate, are omnipresent in many branches of science-and in physics in particular. Flat-top solitons are a novel type of bright solitons that have not been well explored in pure nonlinear media. Here, a model of nonlinear Kerr (cubic) media of ultracold atoms with spatially modulated repulsive interactions is proposed and shown to support a vast variety of stable flat-top matter-wave solitons, including one-dimensional flat-top fundamental and multipole solitons, and two-dimensional flat-top fundamental and vortex solitons. We demonstrate that by varying the relevant physical parameters (nonlinearity coefficient and chemical potential), the ordinary bright (Gaussian) solitons can transform into the novel flat-top solitons. The (in)stability domains of the flat-top soliton families are checked by means of linear stability analysis and reconfirmed by direct numerical simulations. This model is generic in the contexts of nonlinear optics and Bose-Einstein condensates, which provides direct experimental access to observe the predicted solutions. (C) 2019 Optical Society of America
入藏号: WOS:000478057200062
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ceng, jian hua                  0000-0003-0189-1856
Zeng, Liangwei                  0000-0001-9603-1845

ISSN: 0740-3224
eISSN: 1520-8540
________________________________________
第 120 条,共 344 条
标题: Semantic Descriptions of High-Resolution Remote Sensing Images
作者: Wang, BQ (Wang, Binqiang); Lu, XQ (Lu, Xiaoqiang); Zheng, XT (Zheng, Xiangtao); Li, XL (Li, Xuelong)
来源出版物: IEEE GEOSCIENCE AND REMOTE SENSING LETTERS 卷: 16 期: 8 页: 1274-1278 DOI: 10.1109/LGRS.2019.2893772 出版年: AUG 2019
摘要: Image captioning has attracted more and more attention in remote sensing filed since it provides more specific information than traditional tasks, such as classification. Though image captioning has gained some developments in recent years, it is difficult to describe the image in one simple sentence. To relieve the limitation, a novel captioning task is proposed and a novel framework is proposed to solve the novel task. The proposed framework uses semantic embedding to measure the image representation and the sentence representation. The captioning performance is improved by a proposed sentence representation (collective representation). Experimental results and human evaluations on three captioning data sets in remote sensing field demonstrate that the proposed framework can lead to advancement in image captioning results.
入藏号: WOS:000476814300021
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Lu, Xiaoqiang                  0000-0002-7037-5188
Wang, Binqiang                  0000-0001-9406-167X

ISSN: 1545-598X
eISSN: 1558-0571
________________________________________
第 121 条,共 344 条
标题: Hierarchical and Robust Convolutional Neural Network for Very High-Resolution Remote Sensing Object Detection
作者: Zhang, YL (Zhang, Yuanlin); Yuan, Y (Yuan, Yuan); Feng, YC (Feng, Yachuang); Lu, XQ (Lu, Xiaoqiang)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 8 页: 5535-5548 DOI: 10.1109/TGRS.2019.2900302 出版年: AUG 2019
摘要: Object detection is a basic issue of very high-resolution remote sensing images (RSIs) for automatically labeling objects. At present, deep learning has gradually gained the competitive advantage for remote sensing object detection, especially based on convolutional neural networks (CNNs). Most of the existing methods use the global information in the fully connected feature vector and ignore the local information in the convolutional feature cubes. However, the local information can provide spatial information, which is helpful for accurate localization. In addition, there are variable factors, such as rotation and scaling, which affect the object detection accuracy in RSIs. In order to solve these problems, this paper presents a hierarchical robust CNN. First, multiscale convolutional features are extracted to represent the hierarchical spatial semantic information. Second, multiple fully connected layer features are stacked together so as to improve the rotation and scaling robustness. Experiments on two data sets have shown the effectiveness of our method. In addition, a largescale high-resolution remote sensing object detection data set is established to make up for the current situation that the existing data set is insufficient or too small.
入藏号: WOS:000476805800025
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lu, Xiaoqiang                  0000-0002-7037-5188
Zhang, Yuanlin                  0000-0003-0960-3636

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 122 条,共 344 条
标题: Numerical and Experimental Characterization of Radiation Mode of 45 degrees Tilted Fiber Grating
作者: Qin, HB (Qin, Huabao); He, QY (He, Qinyun); Xing, ZK (Xing, Zhikun); Guo, X (Guo, Xi); Yan, ZJ (Yan, Zhijun); Sun, QZ (Sun, Qizhen); Zhou, KM (Zhou, Kaiming); Wang, HS (Wang, Hushan); Liu, DM (Liu, Deming); Zhang, L (Zhang, Lin)
来源出版物: JOURNAL OF LIGHTWAVE TECHNOLOGY 卷: 37 期: 15 页: 3777-3783 DOI: 10.1109/JLT.2019.2920680 出版年: AUG 1 2019
摘要: In this paper, we have numerically and experimentally investigated the radiation mode of 45 degrees tilted fiber grating (45 degrees TFG). By introducing the axial distributions into the volume current method, we have established a three-dimensional theoretical model to analyze spatial distributions of the radiation mode of 45 degrees TFG, and measured the radiation mode spatial distributions in experiment. Both numerical and experimental results show that the radiation mode of 45 degrees TFG exhibits an exponential reduction along the fiber axial direction, and a quasi-Gaussian profile along the radial direction of fiber. Additionally, we have also measured the detailed polarization-dependent azimuthal intensity distributions of radiation modes of both s- and p-polarized core modes. The degree of polarization of radiation mode is around 99.886%, which is independent of the length and the polarization extinction ratio of the grating. Moreover, for the first time, we have experimentally observed a very weak p-polarized component existing in the radiation mode, which has matched well with the simulation results.
入藏号: WOS:000476807600011
ISSN: 0733-8724
eISSN: 1558-2213
________________________________________
第 123 条,共 344 条
标题: 23.9 W, 985 fs Chirped Pulse Amplification System Based on Yb:YAG Rod Amplifier
作者: Wang, NN (Wang, Na Na); Wang, XL (Wang, Xiang Lin); Zhang, T (Zhang, Ting); Zhang, W (Zhang, Wei); Hu, XH (Hu, Xiao Hong); Yuan, H (Yuan, Hao); Li, F (Li, Feng); Wang, YS (Wang, Yi Shan); Zhao, W (Zhao, Wei)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 4 文献号: 1503307 DOI: 10.1109/JPHOT.2019.2926840 出版年: AUG 2019
摘要: A stable and simple Yb:YAG rod amplifier based on chirped pulse amplification in a water cooling system has been demonstrated. The output power of 38 W at a 250 kHz repetition rate with a spectrum width of 4 nm centered at 1030 nm, which support Fourier-transform limited pulse duration of 389 fs has been generated. The compressed power of 23.9 W with pulse duration of 985 fs has been obtained with a chirped volume Bragg grating compressor. The power stability is measured to be 1.414% when the output power is 35 W. The system is worthwhile to popularize for its good performance and inexpensive cost.
入藏号: WOS:000476779700001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Xianglin                  0000-0003-3831-9570
Feng, Li                  0000-0003-0846-7273

ISSN: 1943-0655
eISSN: 1943-0647
________________________________________
第 124 条,共 344 条
标题: Parallel Fourier ptychographic microscopy for high-throughput screening with 96 cameras (96 Eyes)
作者: Chan, ACS (Chan, Antony C. S.); Kim, J (Kim, Jinho); Pan, A (Pan, An); Xu, H (Xu, Han); Nojima, D (Nojima, Dana); Hale, C (Hale, Christopher); Wang, SL (Wang, Songli); Yang, CHE (Yang, Changhuei)
来源出版物: SCIENTIFIC REPORTS 卷: 9 文献号: 11114 DOI: 10.1038/s41598-019-47146-z 出版年: JUL 31 2019
摘要: We report the implementation of a parallel microscopy system (96 Eyes) that is capable of simultaneous imaging of all wells on a 96-well plate. The optical system consists of 96 microscopy units, where each unit is made out of a four element objective, made through a molded injection process, and a low cost CMOS camera chip. By illuminating the sample with angle varying light and applying Fourier Ptychography, we can improve the effective brig htfield imaging numerical aperture of the objectives from 0.23 to 0.3, and extend the depth of field from +/- 5 mu m to +/- 15 mu m. The use of Fourier Ptychography additionally allows us to computationally correct the objectives' aberrations out of the rendered images, and provides us with the ability to render phase images. The 96 Eyes acquires raw data at a rate of 0.7 frame per second (all wells) and the data are processed with 4 cores of graphical processing units (GPUs; GK210, Nvidia Tesla K80, USA). The system is also capable of fluorescence imaging (excitation = 465 nm, emission = 510 nm) at the native resolution of the objectives. We demonstrate the capability of this system by imaging S1P(1)-eGFP-Human bone osteosarcoma epithelial (U2OS) cells.
入藏号: WOS:000477950800037
PubMed ID: 31366957
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Hale, Christopher         A-6633-2009         0000-0002-2360-7759
Chan, Antony C.                  0000-0002-5104-261X

ISSN: 2045-2322
________________________________________
第 125 条,共 344 条
标题: Influences of second-order and third-order dispersion on spectral properties of mid-infrared wavelength conversion in silicon nitride waveguides
作者: Xie, P (Xie, Peng); Liu, JR (Liu, Jiarui); Wen, Y (Wen, Yu); Wan, ZS (Wan, Zishen); Wang, YS (Wang, Yishan)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 21 文献号: 1950241 DOI: 10.1142/S0217984919502415 出版年: JUL 30 2019
摘要: The influences of second-order dispersion (SOD) and third-order dispersion (TOD) on spectral properties of wavelength conversion based on FWM at mid-infrared region (mid-IR) are theoretically investigated in a silicon nitride waveguide. It is found that the SOD and TOD can affect the frequency shift and temporal profiles of idler pulses. Moreover, the temporal and frequency spectrum of output signal are also discussed with different SODs and TODs. Meanwhile, the numerical simulation results imply that the efficiency of FWM process will be reduced and the wavelength range of phase-match will be shifted due to the change of SOD or TOD.
入藏号: WOS:000477897700003
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 126 条,共 344 条
标题: Signal enhancement of laser-induced breakdown spectroscopy on non-flat samples by single beam splitting
作者: Lei, BY (Lei, Bingying); Wang, J (Wang, Jing); Li, J (Li, Jing); Tang, J (Tang, Jie); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Duan, YX (Duan, Yixiang)
来源出版物: OPTICS EXPRESS 卷: 27 期: 15 页: 20541-20557 DOI: 10.1364/OE.27.020541 出版年: JUL 22 2019
摘要: A single-beam-splitting approach was employed to enhance the signal intensity of LIBS under the extreme condition of laser beam grazing the surface of non-flat samples. Examining the time-integrated emission spectra shows that I-Split/ I-Single enhancement factors of 2.5 and 3.5 were achieved at the laser energy of 33 mJ for aluminium alloy and brass. respectively. This factor first increases, reaches its maximum at 33 mJ, and drops gradually with the laser energy further increased. The mechanisms behind the enhanced optical emission and the enhancement factor evolution are discussed by using the proposed laser ablation model and laser-supported detonation (LSD) wave model, respectively. Examining the time-resolved emission spectra show that enhancement effect exists across all the plasma expansion process and the split beam mode allows for a longer plasma lifetime. A remarkable feature is that the trailing phenomenon emerging in the single beam mode vanishes due to the interaction between the plasmas generated by the grazing incident and normally incident laser beams in the split beam mode. The underlying cause is probably that the plasma plume produced by the normally incident laser beam prevents the grazing incident laser beam from further propagating and ablating the sample surface below. These findings not only give an insight into the plasma generation and evolution at grazing incidence of laser beam on sample surface but also provide a more reliable method for outdoor LIBS measurement of irregular samples. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000476652500037
PubMed ID: 31510146
ISSN: 1094-4087
________________________________________
第 127 条,共 344 条
标题: On-line dynamic detection in the column chromatography separation based on an optical fiber surface plasmon resonance sensor
作者: Cao, JM (Cao, Jiaming); Yang, XH (Yang, Xinghua); Teng, PP (Teng, Pingping); Liu, ZH (Liu, Zhihai); Yang, J (Yang, Jun); Zhang, JZ (Zhang, Jianzhong); Zhang, Y (Zhang, Yu); Luo, M (Luo, Meng); Gao, DH (Gao, Danheng); Kong, DP (Kong, Depeng); Xia, SY (Xia, Siyuan); Zhao, EM (Zhao, Enming); Yuan, LB (Yuan, Libo)
来源出版物: APPLIED OPTICS 卷: 58 期: 21 页: 5774-5779 DOI: 10.1364/AO.58.005774 出版年: JUL 20 2019
摘要: In this design, we introduced a surface plasmon resonance (SPR) fiber-sensing probe into a column chromatography (CC) system to realize on-line dynamic detection in sample separation. The refractive index of the gel around the probe would be adjusted dynamically by the concentration change of the sample during CC separation. To demonstrate the separation and on-line detection process, bovine serum albumin (BSA) and riboflavin-5-phosphate sodium (FMN-Na) are chosen as the analytes in a Sephadex gel filtration chromatography system. The results show that the apparent reversible shift of the SPR spectrum can characterize the separation process. Specifically, the separated BSA with an outflow time of 8 min can cause a resonance wavelength shift of 15.5 nm, and the FMN-Na with an outflow time of 26 min can cause a shift of 8.4 nm. This on-line dynamic detection of SPR spectra has great potential to save time and simplify the analysis process compared to the com- plex thin layer chromatography detection steps in traditional manual CC. (C) 2019 Optical Society of America
入藏号: WOS:000476625600022
PubMed ID: 31503880
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 128 条,共 344 条
标题: Simple method for simultaneous long-term stabilization of relative timing and carrier-envelope phase in waveform synthesis
作者: Huang, P (Huang, Pei); Fang, SB (Fang, Shaobo); Gao, YT (Gao, Yitan); Zhao, K (Zhao, Kun); Hou, X (Hou, Xun); Wei, ZY (Wei, Zhiyi)
来源出版物: APPLIED PHYSICS LETTERS 卷: 115 期: 3 文献号: 031102 DOI: 10.1063/1.5083239 出版年: JUL 15 2019
摘要: We present an f-to-2f interferometry method to simultaneously measure and control the relative timing (RT) and carrier-envelope phase (CEP) of an arbitrarily tailored optical-field waveform. Long-term stabilization of the phase-locking system results in a CEP stability of 280 mrad and a RT stability of 110 attosecond over 8h at a repetition rate of 1kHz. The synthesized optical field characterized by a transient-grating frequency-resolved optical gating delivers 3.8-fs near single-cycle waveforms. This technique constitutes a versatile tool for coherent pulse synthesis, which can be applied in experiments using a dual-color light field for high-harmonic generation and attosecond timing precision pump-probe spectroscopy.
入藏号: WOS:000476586900002
ISSN: 0003-6951
eISSN: 1077-3118
________________________________________
第 129 条,共 344 条
标题: Nonlinear reconstruction of weak optical diffused images under turbid water
作者: Wang, ZL (Wang, Zhaolu); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Zhang, YB (Zhang, Yongbin); Chi, J (Chi, Jiao)
来源出版物: OPTICS LETTERS 卷: 44 期: 14 页: 3502-3505 DOI: 10.1364/OL.44.003502 出版年: JUL 15 2019
摘要: Forward scattering noise may degrade the imaging resolution and diffuse the image in turbid water. The reconstruction of diffused images hidden by forward scattering noise is crucial for underwater imaging. To overcome the limitation of forward scattering for optical imaging in turbid water, a nonlinear image reconstruction technology is proposed in the experiment. We experimentally demonstrated the reconstruction of the diffused images under turbid water via signal seeded incoherent modulation instability (MI) in a nonlinear photorefractive crystal. The reconstructed image with high quality and the minimum resolution of 28.51 lp/mm are observed in the experiment. This is the first time, to the best of our knowledge, that a spatial MI effect is used to process underwater weak optical diffused images in the experiment. (C) 2019 Optical Society of America
入藏号: WOS:000475678500023
PubMed ID: 31305558
ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 130 条,共 344 条
标题: Retrieval of marine inorganic particle concentrations in turbid waters using polarization signals
作者: Liu, J (Liu, Jia); Liu, JH (Liu, Jiahang); He, XQ (He, Xianqiang); Tian, LQ (Tian, Liqiao); Bai, Y (Bai, Yan); Chen, TQ (Chen, Tieqiao); Wang, YH (Wang, Yihao); Zhu, F (Zhu, Feng); Pan, DL (Pan, Delu)
来源出版物: INTERNATIONAL JOURNAL OF REMOTE SENSING DOI: 10.1080/01431161.2019.1641248 提前访问日期: JUL 2019
摘要: The polarization properties of water-leaving radiance (L-w) contains rich information about hydrosols, which has great potential to improve the retrieval accuracy of oceanic constituents. However, current ocean colour inversion algorithms are only based on the water-leaving radiation intensity, and the polarization properties have been ignored. Here, based on the radiative transfer simulations, the possibility of retrieving suspended particulate matter in turbid waters based on the polarization properties was investigated. The results showed that the degree of polarization (DOP) of the upward radiation just beneath the water surface has significant angular and spectral variations with respect to the observational geometries, inorganic particle concentrations, solar zenith angles and aerosol optical thicknesses (AOTs). The directional variations in DOP along with viewing zenith angles are typically characterized by a double peak feature with a maximum of 0.5 in the principal plane. In addition, the DOP in the visible bands is highly sensitive to inorganic particle concentrations. The DOP gradually decreases from 412 nm to 555 nm and increases with wavelengths beyond 555 nm, particularly for wavelengths larger than 620 nm. An empirical relationship between the DOP at 670 nm and the inorganic particle concentration was established for different viewing geometries with determination coefficient (R-2) up to 0.9996. Overall, our simulation results indicate that the polarization property of underwater upward radiance has great potential for suspended particulate matter retrieval in coastal waters.
入藏号: WOS:000476206900001
ISSN: 0143-1161
eISSN: 1366-5901
________________________________________
第 131 条,共 344 条
标题: Electron-transfer cascade from CdSe@ZnSe core-shell quantum dot accelerates photoelectrochemical H-2 evolution on TiO2 nanotube arrays
作者: Jia, J (Jia, Jia); Xue, P (Xue, Peng); Hu, XY (Hu, Xiaoyun); Wang, YS (Wang, Yishan); Liu, EZ (Liu, Enzhou); Fan, J (Fan, Jun)
来源出版物: JOURNAL OF CATALYSIS 卷: 375 页: 81-94 DOI: 10.1016/j.jcat.2019.05.028 出版年: JUL 2019
摘要: A novel TiO2-CdSe-ZnSe electron-transfer cascade heterostructure with nanoscale precision is synthesized for hydrogen evolution, exhibiting an obvious hierarchical absorption and improved separation efficiency for photocarriers. The key to this constructed structure lies in the in-situ deposition of CdSe quantum-dots onto the surface of TiO2 followed by the epitaxial growth of a ZnSe shell. In this conditions, the CdSe core can serve as a buffer layer for the electrons on the conduction band of the ZnSe shell, enabling them to rapidly migrate to the TiO2 and later to the opposite electrode to produce H-2; meanwhile, due to high injection efficiency in the cascade type II structure, holes from TiO2 are transferred to the electrolyte interface, where the oxidation reaction of hole trapping scavenger occurs. Surprisingly, this heterostructure shows a significantly enhanced photocurrent density (1.45 mA cm(-2)), favorable H-2 production rates (252 mu mol h(-1) cm(-2)) and moderate durability under light irradiation. (C) 2019 Elsevier Inc. All rights reserved.
入藏号: WOS:000486104500009
ISSN: 0021-9517
eISSN: 1090-2694
________________________________________
第 132 条,共 344 条
标题: Does being multi-headed make you better at solving problems? A survey of Physarum-based models and computations
作者: Gao, C (Gao, Chao); Liu, C (Liu, Chen); Schenz, D (Schenz, Daniel); Li, XL (Li, Xuelong); Zhang, ZL (Zhang, Zili); Jusup, M (Jusup, Marko); Wang, Z (Wang, Zhen); Beekman, M (Beekman, Madeleine); Nakagaki, T (Nakagaki, Toshiyuki)
来源出版物: PHYSICS OF LIFE REVIEWS 卷: 29 页: 1-26 DOI: 10.1016/j.plrev.2018.05.002 出版年: JUL 2019
摘要: Physarum polycephalum, a single-celled, multinucleate slime mould, is a seemingly simple organism, yet it exhibits quasiintelligent behaviour during extension, foraging, and as it adapts to dynamic environments. For these reasons, Physarum is an attractive target for modelling with the underlying goal to uncover the physiological mechanisms behind the exhibited quasi-intelligence and/or to devise novel algorithms for solving complex computational problems. The recent increase in modelling studies on Physarum has prompted us to review the latest developments in this field in the context of modelling and computing alike. Specifically, we cover models based on (i) morphology, (ii) taxis, and (iii) positive feedback dynamics found in top-down and bottom-up modelling techniques. We also survey the application of each of these core features of Physarum to solving difficult computational problems with real-world applications. Finally, we highlight some open problems in the field and present directions for future research. (C) 2018 Published by Elsevier B.V.
入藏号: WOS:000483646000001
PubMed ID: 29857934
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Beekman, Madeleine         AAF-8574-2019         0000-0002-9040-3756
Jusup, Marko         S-8567-2018         0000-0002-0777-0425
Beekman, Madeleine         A-3983-2011         0000-0002-9040-3756
Schenz, Daniel                  0000-0003-2930-641X
Li, Xuelong                  0000-0002-0019-4197

ISSN: 1571-0645
eISSN: 1873-1457
________________________________________
第 133 条,共 344 条
标题: Physarum inspires research beyond biomimetic algorithms Reply to comments on "Does being multi-headed make you better at solving problems?"
作者: Gao, C (Gao, Chao); Liu, C (Liu, Chen); Schenz, D (Schenz, Daniel); Li, XL (Li, Xuelong); Zhang, ZL (Zhang, Zili); Jusup, M (Jusup, Marko); Wang, Z (Wang, Zhen); Beekman, M (Beekman, Madeleine); Nakagaki, T (Nakagaki, Toshiyuki)
来源出版物: PHYSICS OF LIFE REVIEWS 卷: 29 页: 51-54 DOI: 10.1016/j.plrev.2019.07.002 出版年: JUL 2019
摘要: We look at a recent expansion of Physarum research from inspiring biomimetic algorithms to serving as a model organism in the evolutionary study of perception, memory, learning, and decision making. (C) 2019 Elsevier B.V. All rights reserved.
入藏号: WOS:000483646000010
PubMed ID: 31307950
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Jusup, Marko         S-8567-2018         0000-0002-0777-0425
Li, Xuelong         Z-3785-2019         
Beekman, Madeleine         AAF-8574-2019         0000-0002-9040-3756
Schenz, Daniel                  0000-0003-2930-641X

ISSN: 1571-0645
eISSN: 1873-1457
________________________________________
第 134 条,共 344 条
标题: A Filamentary Plasma Jet Generated by Argon Dielectric-Barrier Discharge in Ambient Air
作者: Li, J (Li, Jing); Lei, BY (Lei, Bingying); Wang, J (Wang, Jing); Zhang, TY (Zhang, Tongyi); Tang, J (Tang, Jie); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Duan, YX (Duan, Yixiang)
来源出版物: IEEE TRANSACTIONS ON PLASMA SCIENCE 卷: 47 期: 7 页: 3134-3140 DOI: 10.1109/TPS.2019.2916187 子辑: 2 出版年: JUL 2019
摘要: A filamentary plasma jet was produced by a cylindrical dielectric-barrier discharge ( DBD) equipped with a thin quartz tube. This plasma jet consists of many filaments, and the filaments bifurcate into thinner branches close to the ground electrode. Only a single filament is produced in each current pulse, and this filament is distorted in the long gas gap. The maximum electron density in the filament is on the order of 10(15)cm(-3). Optical emission examination shows a decrease of optical emissions from OH and Ar but an increase of optical emissions from N2 along the plasma jet. The vapor in the working gas argon rather than in the ambient air dominates the optical emissions from the de-excitation of OH along the plasma jet. Near the ground electrode, the nitrogen emission spectra mainly resulted from the direct electron effect on the ground state or metastable nitrogen and the collisions between nitrogen metastables. The rotational temperature is lower than the vibrational temperature but much higher than the room temperature. This feature makes the filamentary plasma jet only suitable for processing samples bearing high temperature.
入藏号: WOS:000474565000003
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
zhang, tong yi                  0000-0002-7908-8046
Tang, Jie                  0000-0003-2162-6830

ISSN: 0093-3813
eISSN: 1939-9375
________________________________________
第 135 条,共 344 条
标题: Multi-wavelength multi-focus Fresnel solar concentrator with square uniform irradiance: design and analysis
作者: Jiang, YR (Jiang, Yanru); Xie, QK (Xie, Qingkun); Qu, ES (Qu, Enshi); Ren, LY (Ren, Liyong); Liang, J (Liang, Jian); Wang, L (Wang, Ling)
来源出版物: APPLIED OPTICS 卷: 58 期: 19 页: 5206-5212 DOI: 10.1364/AO.58.005206 出版年: JUL 1 2019
摘要: In this paper, a two-step optical design method is proposed to build a superior Fresnel-based photovoltaic concentrator for enhancing light conversion efficiency with the multi-junction solar cell. In the first step, we orthogonally segment a traditional Fresnel concentrator and remove the two normal stripe bands around the horizontal and vertical axes, as well as recombine the resultant four quadrants again. By using such a specific Fresnel concentrator design, a square light pattern can be constructed owing to the off-axis non-rotational symmetric superposition of light. In the second step, as for the response wavelengths of a specific triple-junction solar cell, we further carry out a triple-wavelength and multi-focus design of the above Fresnel concentrator for improving the uniformity of light distribution on the solar cell. To show the validity of this novel design method, a solar concentrator, with typical design parameters including the geometrical concentration ratio of 800x and the F-number of 0.775, is designed and simulated. As a result, theoretical irradiance uniformity up to 87% is obtained. In addition, considering the fact that no second optical element is involved in the concentrator system, our design method inherently has the advantages of good compactness, high efficiency, low cost, and ease for mass-production. We believe that such a concentrator is of great significance to solar cells for high conversion efficiency of light in the concentrator photovoltaic system. (C) 2019 Optical Society of America
入藏号: WOS:000473324200010
PubMed ID: 31503615
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
, Jian                  0000-0002-0324-1497
ren, li yong         F-5518-2014         0000-0002-7547-7511

ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 136 条,共 344 条
标题: Mechanical rotation and bending sensing by chiral long-period grating based on an axis-offset rotating optical fiber
作者: Wang, RD (Wang, Ruiduo); Ren, ZY (Ren, Zhaoyu); Kong, XD (Kong, Xudong); Kong, DP (Kong, Depeng); Hu, BW (Hu, Baowen); He, ZQ (He, Zhengquan)
来源出版物: APPLIED PHYSICS EXPRESS 卷: 12 期: 7 文献号: 072013 DOI: 10.7567/1882-0786/ab2a20 出版年: JUL 1 2019
摘要: A chiral long-period fiber grating (CLPFG) was fabricated by rotating the standard single mode fiber that was fixed on two fiber holders with an axis-offset. We investigated the performance of CLPFGs by sensing the mechanical twist, bending, and liquid refractive index experimentally. A wide twist sensing range of +/- 720 degrees and 26.7 nm wavelength tuning range were achieved. Compared with tapered long-period fiber grating, the bending sensitivity of CLPFG is 5 times higher. Considering the simple and flexible fabrication process and low cost, this CLPFG may offer a simple and alternative choice for sensing mechanical deformation in industrial applications. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000473507900002
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Ruiduo                  0000-0003-4420-4737

ISSN: 1882-0778
eISSN: 1882-0786
________________________________________
第 137 条,共 344 条
标题: Real-Time Evolution Dynamics of Double-Pulse Mode-Locking
作者: Wang, GM (Wang, Guomei); Chen, GW (Chen, Guangwei); Li, WL (Li, Wenlei); Zeng, C (Zeng, Chao)
来源出版物: IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS 卷: 25 期: 4 文献号: 1100504 DOI: 10.1109/JSTQE.2019.2922828 出版年: JUL-AUG 2019
摘要: By means of the emerging dispersive Fourier transform technique, we captured the pulse-resolved spectral evolution dynamics of double-pulse mode-locking in a single-walled carbon nanotube based Er-doped fiber laser from the initial fluctuations, monitoring the evolution process up to 10 s (corresponding to similar to 260 million roundtrips) discontinuously. Two distinctly different evolutionary types of double-pulse mode-locking have been investigated in detail: splitting from one pulse and forming simultaneously. Relaxation oscillations, beating dynamics, transient bound state, spectral broadening, and variation of pulse interval have been observed in the evolution processes of the double-pulse mode-locking. Our study will be helpful for the further research of double-pulse mode-locking.
入藏号: WOS:000473595900001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zeng, Chao                  0000-0003-0097-6399

ISSN: 1077-260X
eISSN: 1558-4542
________________________________________
第 138 条,共 344 条
标题: A Deep Scene Representation for Aerial Scene Classification
作者: Zheng, XT (Zheng, Xiangtao); Yuan, Y (Yuan, Yuan); Lu, XQ (Lu, Xiaoqiang)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 7 页: 4799-4809 DOI: 10.1109/TGRS.2019.2893115 出版年: JUL 2019
摘要: As a fundamental problem in earth observation, aerial scene classification tries to assign a specific semantic label to an aerial image. In recent years, the deep convolutional neural networks (CNNs) have shown advanced performances in aerial scene classification. The successful pretrained CNNs can he transferable to aerial images. However, global CNN activations may lack geometric invariance and, therefore, limit the improvement of aerial scene classification. To address this problem, this paper proposes a deep scene representation to achieve the invariance of CNN features and further enhance the discriminative power. The proposed method: 1) extracts CNN activations from the last convolutional layer of pretrained CNN; 2) performs multiscale pooling (MSP) on these activations; and 3) builds a holistic representation by the Fisher vector method. MSP is a simple and effective multiscale strategy, which enriches multiscale spatial information in affordable computational time. The proposed representation is particularly suited at aerial scenes and consistently outperforms global CNN activations without requiring feature adaptation. Extensive experiments on five aerial scene data sets indicate that the proposed method, even with a simple linear classifier, can achieve the state-of-the-art performance.
入藏号: WOS:000473436000050
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 139 条,共 344 条
标题: Similarity Constrained Convex Nonnegative Matrix Factorization for Hyperspectral Anomaly Detection
作者: Zhang, WX (Zhang, Wuxia); Lu, XQ (Lu, Xiaoqiang); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 7 页: 4810-4822 DOI: 10.1109/TGRS.2019.2893116 出版年: JUL 2019
摘要: Hyperspectral anomaly detection is very important in the remote sensing domain. The representation-based anomaly method is one of the most important hyperspectral anomaly detection methods, which uses reconstruction errors (REs) to detect anomalies. REs are affected by the basis matrix and its corresponding coefficient matrix. Mixed pixels exist because of the low-spatial resolution of hyperspectral images. The RE is not large enough to correctly distinguish the pixel difficult to classify when the basis matrix is composed of pixels. Moreover, its corresponding coefficients cannot indicate whether pixels are pure or mixed and the abundances of mixed pixels. To address the above-mentioned problems, endmembers referring to pure or relatively pure spectral signatures are explored to build the basis matrix. The RE based on the basis matrix of endmembers is much larger for the anomalous pixel difficult to correctly classify. Furthermore, its corresponding coefficient matrix of endmembers has physical meanings. Hence, a novel hyperspectral anomaly detection based on similarity constrained convex nonnegative matrix factorization is proposed from the perspective of endmembers for the first time. First, convex nonnegative matrix factorization (CNMF) is employed to obtain endmembers of background. Then, CNMF is constrained by the similarity regularization that considers different contributions of endmembers to the pixel under test to acquire the more accurate and meaningful coefficient matrix. Finally, anomalies are detected by calculating REs. The proposed algorithm is verified on both simulated and real data sets. Experimental results show that our proposed algorithm outperforms other state-of-the-art algorithms.
入藏号: WOS:000473436000051
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 140 条,共 344 条
标题: Gain characteristics of a high nonlinearity graphene silicon-based hybrid waveguide
作者: Chen, HJ (Chen, Hongji); Liu, HJ (Liu, Hongjun); Wang, ZL (Wang, Zhaolu); Huang, N (Huang, Nan); Huo, YP (Huo, Yiping)
来源出版物: JAPANESE JOURNAL OF APPLIED PHYSICS 卷: 58 期: 7 文献号: 070908 DOI: 10.7567/1347-4065/ab2a7c 出版年: JUL 1 2019
摘要: We demonstrate a phase-sensitive amplifier based on a high nonlinearity graphene silicon-based hybrid waveguide. Dispersion characteristics of the phase-sensitive amplifier are adjustable via chemical potential of the graphene, and the zero dispersion point right shifts with the chemical potential increasing. Single-trench waveguide structure makes the TE mode strictly limited to the trench. The effective mode area is 0.25 mu m(2). An organic material with low two-photon absorption and high Kerr index is filled in the trench to provide a large nonlinear parameter of 3500 W-1 m(-1). The proposed amplifier has a gain of 35 dB with a length of 1.25 mm. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000474301600001
ISSN: 0021-4922
eISSN: 1347-4065
________________________________________
第 141 条,共 344 条
标题: Ultrashort Bessel beam photoinscription of Bragg grating waveguides and their application as temperature sensors
作者: Zhang, GD (Zhang, Guodong); Cheng, GH (Cheng, Guanghua); Bhuyan, MK (Bhuyan, Manoj K.); D'Amico, C (D'Amico, Ciro); Wang, YS (Wang, Yishan); Stoian, R (Stoian, Razvan)
来源出版物: PHOTONICS RESEARCH 卷: 7 期: 7 页: 806-814 DOI: 10.1364/PRJ.7.000806 出版年: JUL 1 2019
摘要: Ultrashort pulsed Bessel beams with intrinsic nondiffractive character and potential strong excitation confinement down to 100 nm can show a series of advantages over Gaussian beams in fabricating efficient Bragg grating waveguides (BGWs). In this work, we focus on parameter management for the inscription of efficient BGWs using the point-by-point method employing Bessel beams. Due to their high aspect ratio, the resulting one-dimensional void-like structures can section the waveguides and interact efficiently with the optical modes. Effective first-order BGWs with low birefringence can then be fabricated in bulk fused silica. By controlling the size and the relative location of grating voids via the Bessel pulse energy and scan velocities, the resonant behaviors of BGWs can be well regulated. A high value of 34 dB for 8 mm length is achieved. A simple predictive model for BGWs is proposed for analyzing the influences of processing parameters on the performance of BGWs. The technique permits multiplexing several gratings in the same waveguide. Up to eight grating traces were straightforwardly inscribed into the waveguide in a parallel-serial combined mode, forming the multiplex BGWs. As an application, the multiplex BGW sensor with two resonant peaks is proposed and fabricated for improving the reliability of temperature detection. (C) 2019 Chinese Laser Press
入藏号: WOS:000473345500017
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Stoian, Razvan                  0000-0003-2107-9515

ISSN: 2327-9125
________________________________________
第 142 条,共 344 条
标题: Robust Subspace Clustering by Cauchy Loss Function
作者: Li, XL (Li, Xuelong); Lu, QM (Lu, Quanmao); Dong, YS (Dong, Yongsheng); Tao, DC (Tao, Dacheng)
来源出版物: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 卷: 30 期: 7 页: 2067-2078 DOI: 10.1109/TNNLS.2018.2876327 出版年: JUL 2019
摘要: Subspace clustering is a problem of exploring the low-dimensional subspaces of high-dimensional data. State-ofthe-art approaches are designed by following the model of spectral clustering-based method. These methods pay much attention to learn the representation matrix to construct a suitable similarity matrix and overlook the influence of the noise term on subspace clustering. However, the real data are always contaminated by the noise and the noise usually has a complicated statistical distribution. To alleviate this problem, in this paper, we propose a subspace clustering method based on Cauchy loss function (CLF). Particularly, it uses CLF to penalize the noise term for suppressing the large noise mixed in the real data. This is due to that the CLF's influence function has an upper bound that can alleviate the influence of a single sample, especially the sample with a large noise, on estimating the residuals. Furthermore, we theoretically prove the grouping effect of our proposed method, which means that highly correlated data can he grouped together. Finally, experimental results on five real data sets reveal that our proposed method outperforms several representative clustering methods.
入藏号: WOS:000472605500012
PubMed ID: 30418925
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         

ISSN: 2162-237X
eISSN: 2162-2388
________________________________________
第 143 条,共 344 条
标题: Describing Video With Attention-Based Bidirectional LSTM
作者: Bin, Y (Bin, Yi); Yang, Y (Yang, Yang); Shen, FM (Shen, Fumin); Xie, N (Xie, Ning); Shen, HT (Shen, Heng Tao); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON CYBERNETICS 卷: 49 期: 7 页: 2631-2641 DOI: 10.1109/TCYB.2018.2831447 出版年: JUL 2019
摘要: Video captioning has been attracting broad research attention in the multimedia community. However, most existing approaches heavily rely on static visual information or partially capture the local temporal knowledge (e.g., within 16 frames), thus hardly describing motions accurately from a global view. In this paper, we propose a novel video captioning framework, which integrates bidirectional long-short term memory (BiLSTM) and a soft attention mechanism to generate better global representations for videos as well as enhance the recognition of lasting motions in videos. To generate video captions, we exploit another long-short term memory as a decoder to fully explore global contextual information. The benefits of our proposed method are two fold: 1) the BiLSTM structure comprehensively preserves global temporal and visual information and 2) the soft attention mechanism enables a language decoder to recognize and focus on principle targets from the complex content. We verify the effectiveness of our proposed video captioning framework on two widely used benchmarks, that is, microsoft video description corpus and MSR-video to text, and the experimental results demonstrate the superiority of the proposed approach compared to several state-of-the-art methods.
入藏号: WOS:000466062500020
PubMed ID: 29993730
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Li, Xuelong                  0000-0002-0019-4197

ISSN: 2168-2267
eISSN: 2168-2275
________________________________________
第 144 条,共 344 条
标题: Exploiting spatial relation for fine-grained image classification
作者: Qi, L (Qi, Lei); Lu, XQ (Lu, Xiaoqiang); Li, XL (Li, Xuelong)
来源出版物: PATTERN RECOGNITION 卷: 91 页: 47-55 DOI: 10.1016/j.patcog.2019.02.007 出版年: JUL 2019
摘要: Fine-Grained Image Classification (FGIC) aims to distinguish the images within a subordinate category. Recently, many FGIC methods have been proposed and huge progress has been made in the aspects of part detection and feature learning for FGIC. However, FGIC still remains a challenging task due to the large intra-class variance and small inter-class variance. To classify fine-grained images accurately, this paper proposes to exploit spatial relation to capture more discriminative details for FGIC. The proposed method contains two core modules: part selection module and representation module. The part selection module utilizes intrinsic spatial relation between object parts to select object part pairs with high discrimination power. The representation module exploits the interaction between object parts to describe the selected part pairs and construct a semantic image representation for FGIC. The proposed method is evaluated on CUB-200-2011 and FGVC-Aircraft datasets. Experimental results show that the classification accuracy of the proposed method can reach 85.5% on CUB-200-2011 and 86.9% on FGVC-Aircraft respectively, which exceed comparison methods obviously. (C) 2019 Elsevier Ltd. All rights reserved.
入藏号: WOS:000466250400005
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0031-3203
eISSN: 1873-5142
________________________________________
第 145 条,共 344 条
标题: Controllable dot-matrix marking on titanium alloy with anti-reflective micro-structures using defocused femtosecond laser
作者: Sun, XY (Sun, Xiaoyun); Wang, WJ (Wang, Wenjun); Mei, XS (Mei, Xuesong); Pan, AF (Pan, Aifei); Liu, B (Liu, Bin); Li, M (Li, Ming)
来源出版物: OPTICS AND LASER TECHNOLOGY 卷: 115 页: 298-305 DOI: 10.1016/j.optlastec.2019.02.022 出版年: JUL 2019
摘要: This paper reports on the fabrication of marking units of controllable size ranging from 300 to 500 mu m equipped with anti-reflective micro-structures using defocused femtosecond laser on titanium alloy TC4. The results show that the range of diameters of marking units (laser ablation-based craters) goes through three stages with the increase of the pulse number. The craters are too shallow for the first stage and too deep for the third stage to meet the criterion of depth, so the second stage turns out to be the optimal stage of parameter selection, where the diameter and depth of marking units are within a desired range with modification of laser energy and defocusing amount. Besides meeting the marking requirements of the size and morphology, the anti-reflective micro-structures with great color difference are formed on the surface of marking units, which contributes to the high recognition rate. Compared with the conventional marking methods, this method has a great recognition rate without recast layer and micro-cracks. Therefore, the femtosecond laser-based processing would provide a new marking technology with high efficiency and quality.
入藏号: WOS:000465049700040
ISSN: 0030-3992
eISSN: 1879-2545
________________________________________
第 146 条,共 344 条
标题: Optimum design for a novel large mode area fiber with triangle-platform-index core
作者: Miao, XF (Miao, Xiaofang); Wu, P (Wu, Peng); Zhao, BY (Zhao, Baoyin)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 18 文献号: 1950207 DOI: 10.1142/S0217984919502075 出版年: JUN 30 2019
摘要: A triangle-platform-index core fiber is proposed, in which the refractive index distribution in the cross-section of the fiber core is composed of several closely connected triangles and a platform at the outermost layer. The simulation results show that the proposed fiber possesses an extremely large mode field area of 3110 mu m(2) at the wavelength of 1.06 mu m, and achieves single-mode operation state near a bend radius of 17 cm. Furthermore, several different mode field distributions, including Gauss-like distribution, flatten distribution and hollow distribution, are achieved. The proposed fiber can benefit suppressing nonlinear phenomenon to increase the output power level of fiber laser, and promoting special industrial processing.
入藏号: WOS:000473149600011
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 147 条,共 344 条
标题: High-resolution reconstruction of shortwave infrared polarimetric images using the intensity information of visible images
作者: Liang, J (Liang, Jian); Ju, HJ (Ju, Haijuan); Ren, LY (Ren, Liyong); Zhang, WF (Zhang, Wenfei); Yang, LM (Yang, Liming); Bai, ZF (Bai, Zhaofeng); Liang, RG (Liang, Rongguang)
来源出版物: APPLIED OPTICS 卷: 58 期: 18 页: 4866-4870 DOI: 10.1364/AO.58.004866 出版年: JUN 20 2019
摘要: Shortwave infrared (SWIR) polarimetric imaging has been found very effective in various applications. However, the low resolution of the SWIR camera severely limits the capacity of this technique. Image reconstruction methods have been developed to improve the spatial resolution, but these methods typically do not consider the polarized information that the images may contain. In this paper, we propose a high-resolution reconstruction method for SWIR images based on the spatial information of visible images without losing polarized information in the SWIR image. Experimental results demonstrate that this method is feasible to reconstruct high-resolution polarized SWIR images. We have also demonstrated its potential application in image fusion. (C) 2019 Optical Society of America
入藏号: WOS:000472149200007
PubMed ID: 31503802
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhang, Wenfei                  0000-0002-4408-4352

ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 148 条,共 344 条
标题: Tunable gallium nitride-based devices for ultrafast signal processing
作者: Xie, P (Xie, Peng); Wen, Y (Wen, Yu); Yang, WQ (Yang, Wenqiang); Wan, ZS (Wan, Zishen); Liu, JR (Liu, Jiarui); Wang, XY (Wang, Xinyu); Da, SQ (Da, Siqi); Wang, YS (Wang, Yishan)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 17 文献号: 1950187 DOI: 10.1142/S0217984919501872 出版年: JUN 20 2019
摘要: In this paper, we propose a micro-ring resonator model based on gallium nitride (GaN) and graphene, which exhibits tunable properties of nonlinearity. It provides a great bandwidth covering from visible to telecommunication band. Especially, based on the characteristic of GaN, it has unique advantages in shorter wavelength, which is used for demonstrating the ultrafast signal processing including wavelength conversion, temporal amplification and pulse compression. Moreover, the tunable signal processing is achieved via the method of applying additional bias voltage to graphene without changing the geometric dimension of the device. These results have significant potential applications of nonlinear optics and optical communications.
入藏号: WOS:000472138500005
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 149 条,共 344 条
标题: A hollow ring-core polymer optical fiber for supra-high bandwidth data communication
作者: Yuan, Y (Yuan, Yuan); Kong, DP (Kong, Depeng); Wang, LL (Wang, Lili)
来源出版物: OPTICS COMMUNICATIONS 卷: 441 页: 176-184 DOI: 10.1016/j.optcom.2019.02.055 出版年: JUN 15 2019
摘要: Bandwidth of polymer optical fiber (POF) is severely limited in a few gigabits. In order to solve the toughest problem, a new type of POF, named hollow ring-core POF (HRC-POF) is designed and simulated. Compared with the SI-POF and GI-POF, the proposed HRC-POF can be used for supra-high bandwidth data transmission based on OAM-based space division multiplex. Compared with the reported glass-based hollow ring-core fiber, the HRC-POF provides a number of other advantages, such as low processing temperature, simple manufacturing process, and low cost. The simulated results show that a polystyrene-based HRC-POF can support 30 states (including 26 OAM ones) in the vicinity of 670 nm wavelength, which means that the HRC-POF can create a total of 30 channels for data transmission in POF communication.
入藏号: WOS:000461940700029
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 150 条,共 344 条
标题: Chip-integrated metasurface for versatile and multi-wavelength control of light couplings with independent phase and arbitrary polarization
作者: Meng, Y (Meng, Yuan); Hu, FT (Hu, Futai); Liu, ZT (Liu, Zhoutian); Xie, P (Xie, Peng); Shen, YJ (Shen, Yijie); Xiao, QR (Xiao, Qirong); Fu, X (Fu, Xing); Bae, SH (Bae, Sang-Hoon); Gong, ML (Gong, Mali)
来源出版物: OPTICS EXPRESS 卷: 27 期: 12 页: 16425-16439 DOI: 10.1364/OE.27.016425 出版年: JUN 10 2019
摘要: While metasurfaces are now widely considered in free-space optics, their potential for coupling and tailoring guided waves is not fully explored. Here we transfer the Jones matrix method to target versatile on-chip coupling using metasurface-patterned photonic waveguides around the telecommunication wavelength of 1.55 mu m, which can accommodate both propagation and Pancharatnam-Berry phase metasurfaces for guided waves. One can either encode two arbitrary and independent phase profiles to any pair of orthogonal polarizations or deploy complete control over both the phase and polarization of coupled modes. A set of design scenarios synergizing silicon nanoantennas and low-loss silicon-nitride waveguides are proposed, including directional couplers with mode-selectivity and polarization splitters with directionality ranging from 10 to 20 dB. Furthermore, our optimization method can be further extended to cover multiple working wavelengths. Exemplary on-chip color routers are also numerically demonstrated. This chip-integrated metasurface platform further translates the concept of a metasurface into photonic integrated circuits, serving as a positive paradigm for versatile and complete control over waveguide optical signals and motivating chip-scale applications such as polarization/wavelength demultiplexers, optical switches, and multifunctional mode converters. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000470849000030
PubMed ID: 31252868
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Fu, Xing                  0000-0003-1758-1561
Shen, Yijie         F-8311-2019         0000-0002-6700-9902
Meng, Yuan         O-5772-2018         0000-0002-5409-5610

ISSN: 1094-4087

第 151 条,共 344 条
标题: Spectrometer for High Precision Measurement in SteadiQ Extreme Environment in Ocean Optics
作者: Cui, Y (Cui, Ying); He, JH (He, Junhua)
来源出版物: JOURNAL OF COASTAL RESEARCH 特刊: 94 页: 157-160 DOI: 10.2112/SI94-032.1 出版年: SUM 2019
摘要: In ocean remote sensing, the backscattered light received by optical remote sensor carries the light information of the ocean itself. Ocean optical remote sensing is closely related to the spectral characteristics of water body. Ocean spectral characteristics are the basic research and application of ocean remote sensing. The two sensors have a small bandwidth and a bandwidth of 50 to 100 nanometres. In this paper, the spectral structure of the ocean is studied by measurements means and ocean hyperspectral characteristics. It can be found that the changes of offshore body optical parameters can be understood by the spectral characteristic components experiments with different materials in sea water.
入藏号: WOS:000485711600033
ISSN: 0749-0208
eISSN: 1551-5036
________________________________________
第 152 条,共 344 条
标题: A Novel Semi-Soft Decision Scheme for Cooperative Spectrum Sensing in Cognitive Radio Networks
作者: Mi, Y (Mi, Yin); Lu, GY (Lu, Guangyue); Li, YX (Li, Yuxin); Bao, ZQ (Bao, Zhiqiang)
来源出版物: SENSORS 卷: 19 期: 11 文献号: 2522 DOI: 10.3390/s19112522 出版年: JUN 1 2019
摘要: Spectrum sensing (SS) is an essential part of cognitive radio (CR) technology, and cooperative spectrum sensing (CSS) could efficiently improve the detection performance in environments with fading and shadowing effects, solving hidden terminal problems. Hard and Soft decision detection are usually employed at the fusion center (FC) to detect the presence or absence of the primary user (PU). However, soft decision detection achieves better sensing performance than hard decision detection at the expense of the local transmission band. In this paper, we propose a tradeoff scheme between the sensing performance and band cost. The sensing strategy is designed based on three modules. Firstly, a local detection module is used to detect the PU signal by energy detection (ED) and send decision results in terms of 1-bit or 2-bit information. Secondly, and most importantly, the FC estimates the received decision data through a data reconstruction module based on the statistical distribution such that the extra thresholds are not needed. Finally, a global decision module is in charge of fusing the estimated data and making a final decision. The results from a simulation show that the detection performance of the proposed scheme outperforms that of other algorithms. Moreover, savings on the transmission band cost can be made compared with soft decision detection.
入藏号: WOS:000472133300100
PubMed ID: 31159478
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Mi, Yin                  0000-0002-0084-767X

ISSN: 1424-8220
________________________________________
第 153 条,共 344 条
标题: High temperature resistant ultra-short DBR Yb-doped fiber laser
作者: Wang, HS (Wang, Hushan); Xiong, SS (Xiong, Songsong); Song, JZ (Song, Jiazheng); Zhao, FY (Zhao, Fengyan); Yan, ZJ (Yan, Zhijun); Hong, XH (Hong, Xiaohu); Zhang, T (Zhang, Ting); Zhang, W (Zhang, Wei); Zhou, KM (Zhou, Kaiming); Li, C (Li, Cheng); Wang, YS (Wang, Yishan)
来源出版物: APPLIED OPTICS 卷: 58 期: 16 页: 4474-4478 DOI: 10.1364/AO.58.004474 出版年: JUN 1 2019
摘要: We present a distributed Bragg reflector (DBR) Yb-doped fiber laser based on a pair of type IA fiber Bragg gratings (FBGs). The high temperature resistant gratings are fabricated in high absorption hydrogen loaded Yb-doped silica fiber by use of a 244 nm argon laser and phase mask method. The DBR laser, with only 10 mm cavity length, exhibits high signal-noise ratio (SNR) of over 50 dB and can survive at 450 degrees C in a long term with stable output power and central wavelength. Besides, the laser has a relatively low temperature sensitivity of 8.9 pm/degrees C, which contributes to cross-sensitization of stress and temperature. (c) 2019 Optical Society of America.
入藏号: WOS:000469864400042
PubMed ID: 31251260
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 154 条,共 344 条
标题: Low-cost temperature- and strain-insensitive twist sensor based on a hybrid fiber grating structure
作者: Guo, X (Guo, Xi); Xing, ZK (Xing, Zhikun); Qin, HB (Qin, Huabao); Sun, QZ (Sun, Qizhen); Wang, HS (Wang, Hushan); Liu, DM (Liu, Deming); Zhang, L (Zhang, Lin); Yan, ZJ (Yan, Zhijun)
来源出版物: APPLIED OPTICS 卷: 58 期: 16 页: 4479-4483 DOI: 10.1364/AO.58.004479 出版年: JUN 1 2019
摘要: We proposed and experimentally demonstrated a temperature- and strain-insensitive twist sensor based on a hybrid fiber grating structure, in which the hybrid grating structure is constructed with a 45 degrees-tilted fiber grating and a chirped fiber Bragg grating UV-inscribed in a single-mode fiber in series. The sensing performance has been evaluated by experimental and numerical analyses, which are in good consistency. The experimental results show that the hybrid-grating-structure-based twist sensor has a maximum twist sensitivity up to 15.037 dB/rad. Moreover, due to the invariability of the fiber birefringence and the state of polarization of the input light, such sensor has intrinsically low temperature and strain sensitivities of 7.86 x 10(-3) dB/degrees C and 6.7 x 10(-5) dB/mu epsilon, corresponding to the maximum twist measurement error resulting from temperature and strain of 5.2 x 10(-4) rad/degrees C and 4.5 x 10(-6) rad/mu epsilon, respectively. (c) 2019 Optical Society of America.
入藏号: WOS:000469864400043
PubMed ID: 31251261
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 155 条,共 344 条
标题: One-dimensional solitons in fractional Schrodinger equation with a spatially periodical modulated nonlinearity: nonlinear lattice
作者: Zeng, LW (Zeng, Liangwei); Zeng, JH (Zeng, Jianhua)
来源出版物: OPTICS LETTERS 卷: 44 期: 11 页: 2661-2664 DOI: 10.1364/OL.44.002661 出版年: JUN 1 2019
摘要: The existence and stability of stable bright solitons in one-dimensional (1D) fractional media with a spatially periodical modulated Kerr nonlinearity (nonlinear lattice), supported by the recently introduced nonlinear fractional Schrodinger equation, are demonstrated by means of the linear-stability analysis and in direct numerical simulations. Both 1D fundamental and multipole solitons (in forms of dipole and tripole ones) are found, which occupy one or three cells of the nonlinear lattice, respectively, depending on the soliton's power. We find that the profiles of the predicted soliton families are impacted intensely by the Levy index a, and so are their stability. The soliton families are stable if a exceeds a threshold value, below which the balance between fractional-order diffraction and the spatially modulated focusing nonlinearity will be broken. (C) 2019 Optical Society of America
入藏号: WOS:000469838100013
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ceng, jian hua                  0000-0003-0189-1856
Zeng, Liangwei                  0000-0001-9603-1845

ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 156 条,共 344 条
标题: Laser cavity-soliton microcombs
作者: Bao, HL (Bao, Hualong); Cooper, A (Cooper, Andrew); Rowley, M (Rowley, Maxwell); Di Lauro, L (Di Lauro, Luigi); Gongora, JST (Gongora, Juan Sebastian Totero); Chu, ST (Chu, Sai T.); Little, BE (Little, Brent E.); Oppo, GL (Oppo, Gian-Luca); Morandotti, R (Morandotti, Roberto); Moss, DJ (Moss, David J.); Wetzel, B (Wetzel, Benjamin); Peccianti, M (Peccianti, Marco); Pasquazi, A (Pasquazi, Alessia)
来源出版物: NATURE PHOTONICS 卷: 13 期: 6 页: 384-+ DOI: 10.1038/s41566-019-0379-5 出版年: JUN 2019
摘要: Microcavity-based frequency combs, or 'microcombs'(1,2), have enabled many fundamental breakthroughs(3-21) through the discovery of temporal cavity-solitons. These self-localized waves, described by the Lugiato-Lefever equation(22), are sustained by a background of radiation usually containing 95% of the total power(23). Simple methods for their efficient generation and control are currently being investigated to finally establish microcombs as out-of-the-lab tools(24). Here, we demonstrate microcomb laser cavity-solitons. Laser cavity-solitons are intrinsically background-free and have underpinned key breakthroughs in semiconductor lasers(22,25-28). By merging their properties with the physics of multimode systems(29), we provide a new paradigm for soliton generation and control in microcavities. We demonstrate 50-nm-wide bright soliton combs induced at average powers more than one order of magnitude lower than the Lugiato-Lefever soliton power threshold(22), measuring a mode efficiency of 75% versus the theoretical limit of 5% for bright Lugiato-Lefever solitons(23). Finally, we can tune the repetition rate by well over a megahertz without any active feedback.
入藏号: WOS:000468752300013
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
Gongora, Juan Sebastian Totero         J-8601-2015         0000-0003-2300-4218
Wetzel, Benjamin         E-9386-2016         0000-0002-2691-0307
Morandotti, Roberto         J-7954-2013         0000-0001-7717-1519
Pasquazi, Alessia         J-8521-2014         0000-0003-3330-584X
Rowley, Maxwell                  0000-0002-2279-2710
Oppo, Gian-Luca                  0000-0002-5376-4309

ISSN: 1749-4885
eISSN: 1749-4893
________________________________________
第 157 条,共 344 条
标题: Sampling Time Adaptive Single-Photon Compressive Imaging
作者: Wang, H (Wang, Hui); Yan, QR (Yan, Qiurong); Li, B (Li, Bing); Yuan, CL (Yuan, Chenglong); Wang, YH (Wang, Yuhao)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 3 文献号: 6901310 DOI: 10.1109/JPHOT.2019.2912326 出版年: JUN 2019
摘要: We propose a time-adaptive sampling method and demonstrate a samplingtime- adaptive single-photon compressive imaging system. In order to achieve self-adapting adjustment of sampling time, the theory of threshold of light intensity estimation accuracy is deduced. According to this threshold, a sampling control module, based on fieldprogrammable gate array, is developed. Finally, the advantage of the time-adaptive sampling method is proved experimentally. Imaging performance experiments show that the time-adaptive sampling method can automatically adjust the sampling time for the change of light intensity of image object to obtain an image with better quality and avoid speculative selection of sampling time.
入藏号: WOS:000468232700001
ISSN: 1943-0655
eISSN: 1943-0647
________________________________________
第 158 条,共 344 条
标题: Cascaded Fiber Up-Taper Modal Interferometer and Its Application as Fiber Sensor
作者: Dong, SD (Dong, Shandong); Dong, B (Dong, Bo); Yu, CY (Yu, Changyuan); Guo, YX (Guo, Yongxin)
来源出版物: JOURNAL OF LIGHTWAVE TECHNOLOGY 卷: 37 期: 11 特刊: SI 页: 2675-2680 DOI: 10.1109/JLT.2018.2878040 出版年: JUN 1 2019
摘要: A cascaded fiber up-taper interferometer (CFI) is proposed and demonstrated analytically and experimentally. The sensor head of the CFI consists of two cascaded miniaturized fiber up-taper modal interferometers (MMIs). Sensing principle of the CFI is derived based on the transmission matrix method. Conclusions have been achieved that cascading MMIs can effectively improve its thermal sensitivity while strain sensitivity is reduced compared with that of the single MMI. Experimentally, thermal sensitivity of the CFI can reach 112.9 pm/degrees C, and almost two times as big as that of the single MMI. In contrast, its strain sensitivity is only -0.4 pm/mu epsilon, which is only 2/5 as small as that of the single MMI.
入藏号: WOS:000466932100023
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Guo, Yongxin                  0000-0001-8842-5609
Yu, Changyuan         C-2241-2011         0000-0002-3185-0441

ISSN: 0733-8724
eISSN: 1558-2213
________________________________________
第 159 条,共 344 条
标题: Er/Yb Codoped Double Clad Fiber Modal Interferometer and Its Application as Fiber Sensor
作者: Yang, HN (Yang, Hening); Dong, B (Dong, Bo); Zhao, W (Zhao, Wei); Chen, EQ (Chen, Enqing); Wang, YS (Wang, Yishan); Si, JH (Si, Jinhai)
来源出版物: JOURNAL OF LIGHTWAVE TECHNOLOGY 卷: 37 期: 11 特刊: SI 页: 2681-2685 DOI: 10.1109/JLT.2018.2875539 出版年: JUN 1 2019
摘要: An Er/Yb codoped double clad fiber (EYDF) modal interferometer and its application as fiber sensor are proposed and demonstrated. It has the single mode fiber (SMF)-EYDF-SMF structurewith two asymmetrical splice joints. TheMI is sensitive to refractive index (RI) and temperature. Experimental results show that the pump power can tune its operation wavelength, and the higher power will lead to the more redshift of its transmission spectrum. What's more, appropriate change of RI can improve the wavelength tuning range induced by pump power. Moreover, its RI and thermal sensitivities are pump power dependent, and higher pump power will lead to its lower RI sensitivity and lower thermal sensitivity.
入藏号: WOS:000466932100024
ISSN: 0733-8724
eISSN: 1558-2213
________________________________________
第 160 条,共 344 条
标题: Handheld target probe tip center position calibration for target-based vision measurement system
作者: Ma, YY (Ma, Yueyang); Zhao, H (Zhao, Hong); Gu, FF (Gu, Feifei); Zha, CW (Zha, Chunwei); Zhao, ZX (Zhao, Zixin); Zhang, GP (Zhang, Gaopeng); Li, KJ (Li, Kejia)
来源出版物: MEASUREMENT SCIENCE AND TECHNOLOGY 卷: 30 期: 6 文献号: 065013 DOI: 10.1088/1361-6501/ab0c5a 出版年: JUN 2019
摘要: The calibration of the handheld target probe tip center position (PTCP) is an essential procedure in a target-based vision measurement system (T-VMS). At present, handheld PTCP calibration methods typically work via the least squares (LS) method, which is easily affected by noise and may generate a sizable error if placed improperly. This paper proposes a regularized total least squares (RTLS) method for handheld target PTCP calibration. Feature points on the handheld target are first subjected to a robust matching strategy, and then positioned precisely by center extraction deviation compensation. Fixed-radius constraint equations derived from the three-dimensional coordinates of feature points arc then used to establish an errors in variables (EIV) model of the PTCP. Finally, Tikhonov-regularized and L-curve methods are applied to search for the optimal solution of the EIV model, i.e. the PTCP coordinates. The proposed method was applied in the laboratory and on site to test its accuracy. Practical data demonstrated that it can calibrate the PTCP of a handheld target effectively and with better accuracy.
入藏号: WOS:000467826000002
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhao, Zixin                  0000-0002-6597-8873
Ma, Yueyang                  0000-0002-0886-6189

ISSN: 0957-0233
eISSN: 1361-6501
________________________________________
第 161 条,共 344 条
标题: Electronic structure and optical properties of La-doped KSr2Nb5O15: A first-principles investigation
作者: Chen, Q (Chen, Qian); Gao, F (Gao, Feng); Xu, J (Xu, Jie); Cao, SY (Cao, Shuyao); Guo, YT (Guo, Yiting); Cheng, GH (Cheng, Guanghua)
来源出版物: CERAMICS INTERNATIONAL 卷: 45 期: 8 页: 9967-9976 DOI: 10.1016/j.ceramint.2019.02.040 出版年: JUN 2019
摘要: The electronic structure and the anisotropic optical properties of lanthanum doped in KSr2Nb5O15 (KSN-La) were investigated by the first principles calculation dependent on the density functional theory, which was then supported by experiments. With La3+ doping in the KSN lattice, the band gap of KSN-La becomes smaller and the lattice structure transforms from tetragonal to orthorhombic due to the imbalance of charge of the KSN structure affected by the La3+ doping. The analysis of the anisotropic optical properties showed that the value of optical dielectric constant along [001] direction was larger compared to [010] and [100]. The calculated dielectric properties were in good accordance to the experimental results. KSN-La presented a larger dielectric constant, provided that La3+ was able to compensate the vacancies of the A sites of KSN, which were generated during the sintering process, leading to an effective enhancement of the dielectric constant.
入藏号: WOS:000465058500035
ISSN: 0272-8842
eISSN: 1873-3956
________________________________________
第 162 条,共 344 条
标题: A dual-wavelength Q-switched fiber laser based on reduced graphene oxides
作者: Su, YL (Su, Yulong); Huang, XN (Huang, Xinning); Hu, H (Hu, Hui); Wen, Y (Wen, Yu); Xie, XP (Xie, Xiaoping); Si, JH (Si, Jinhai); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei)
来源出版物: LASER PHYSICS 卷: 29 期: 6 文献号: 065101 DOI: 10.1088/1555-6611/ab0d12 出版年: JUN 2019
摘要: This report demonstrates a dual-wavelength stable Q-switched Er-doped fiber (EDF) laser with a reduced graphene oxide (rGO)-based saturable absorber. The rGO is prepared by depositing the graphene oxide on fluorine mica (FM) using a thermal reduction method. The modulation depth and saturable intensity of rGO/FM are measured to be 5.8% and 73.6 MW cm(-2). By employing the rGO/FM film in the EDF laser cavity, stable dual-wavelength Q-switching operation is achieved. The two wavelength peaks locate at 1531.84 nm and 1558.14 nm. The shortest pulse duration is 1.83 mu s. The maximum output power is measured to be 14.65 mW, corresponding to the maximum single pulse energy of 154.34 nJ. The experimental results evidently show that the rGO is a promising type of nonlinear material.
入藏号: WOS:000464397800001
ISSN: 1054-660X
eISSN: 1555-6611
________________________________________
第 163 条,共 344 条
标题: Excessively tilted fiber grating based Fe3O4 saturable absorber for passively mode-locked fiber laser
作者: Wang, HS (Wang, Hushan); Zhao, FY (Zhao, Fengyan); Yan, ZJ (Yan, Zhijun); Hu, XH (Hu, Xiaohong); Zhou, KM (Zhou, Kaiming); Zhang, T (Zhang, Ting); Zhang, W (Zhang, Wei); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Zhang, L (Zhang, Lin); Sun, CD (Sun, Chuandong)
来源出版物: OPTICS EXPRESS 卷: 27 期: 11 页: 15693-15700 DOI: 10.1364/OE.27.015693 出版年: MAY 27 2019
摘要: A novel approach to saturable absorber (SA) formation is presented by taking advantage of the mode coupling property of excessively tilted fiber grating (Ex-TFG). Stable mode-locked operation can be conveniently achieved based on the interaction between Ex-TFG coupled light and deposited ferroferric-oxide (Fe3O4) nanoparticles. The central wavelength, bandwidth and single pulse duration of the output are 1595 nm, 4.05 nm, and 912 fs. respectively. The fiber laser exhibits good long-term stability-with signal-to-noise ratio (SNR) of 67 dB. For the first time, to the best of our knowledge. Ex-TFG based Fe3O4 SA for mode-locked fiber laser is demonstrated. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000469227200051
PubMed ID: 31163762
ISSN: 1094-4087
________________________________________
第 164 条,共 344 条
标题: A porous Au-Ag hybrid nanoparticle array with broadband absorption and high-density hotspots for stable SERS analysis
作者: Li, KG (Li, Kuanguo); Liu, GJ (Liu, Guangju); Zhang, S (Zhang, Sheng); Dai, YQ (Dai, Yanqiu); Ghafoor, S (Ghafoor, Sonia); Huang, WX (Huang, Wanxia); Zua, ZW (Zua, Zewen); Lu, YH (Lu, Yonghua)
来源出版物: NANOSCALE 卷: 11 期: 19 页: 9587-9592 DOI: 10.1039/c9nr01744e 出版年: MAY 21 2019
摘要: Constructing high-density hotspots is of crucial importance in surface enhanced Raman scattering (SERS). In this paper, we present a large-area and broadband porous Au-Ag hybrid nanoparticle array which was fabricated by an ultra-thin alumina mask (UTAM) technique incorporated with annealing and galvanic replacement techniques. Experimental results and numerical simulations demonstrated that the porous Au-Ag hybrid nanoparticle array possessed enormous hotspots for high sensitivity, uniformity, and stability in SERS analysis. A large Raman enhancement factor of 2.2 x 10(7) was achieved with a relative standard deviation (RSD) of 7.7%, leading to excellent reliability for Raman detection. Furthermore, this novel substrate exhibited a long shelf time in an ambient environment and promising practical applications in many SERS-based quantitative analytical and biomedical sensing techniques.
入藏号: WOS:000468868200034
PubMed ID: 31062804
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Kuanguo                  0000-0003-3296-2012

ISSN: 2040-3364
eISSN: 2040-3372
________________________________________
第 165 条,共 344 条
标题: Silicon drift detector applied to X-ray pulsar navigation
作者: Xu, N (Xu, Neng); Sheng, LZ (Sheng, Lizhi); Su, T (Su, Tong); Chen, C (Chen, Chen); Li, Y (Li, Yao); Zhao, BS (Zhao, Baosheng); Liu, CL (Liu, Chunliang)
来源出版物: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 卷: 927 页: 429-434 DOI:10.1016/j.nima.2019.03.007 出版年: MAY 21 2019
摘要: In this paper, a focused detection system for X-ray pulsar-based Navigation (XNAV) is designed based on Silicon Drift Detector (SDD). The detector electronics mainly adopts the digital trapezoidal shaping method to measure the Times-Of-Arrival (TOAs) and energy of photons. The time measurement accuracy is better than 500ns. The energy resolution is 191eV at 8.05keV, and the maximum count rate is 500kcps between 1 and 12keV. In the semi-physical simulation experiment, the filtering of noise photons by energy discrimination significantly improves the correlation degree between the cumulative pulse profile and the standard profile.
入藏号: WOS:000462142700059
ISSN: 0168-9002
eISSN: 1872-9576
________________________________________
第 166 条,共 344 条
标题: Excessively tilted fiber grating-based vector magnetometer
作者: Lu, TA (Lu, Tean); Sun, YZ (Sun, Yuezhen); Moreno, Y (Moreno, Yarien); Sun, QZ (Sun, Qizhen); Zhou, KM (Zhou, Kaiming); Wa, HS (Wa, Hushan); Yan, ZJ (Yan, Zhijun); Liu, DM (Liu, Deming); Zhang, L (Zhang, Lin)
来源出版物: OPTICS LETTERS 卷: 44 期: 10 页: 2494-2497 DOI: 10.1364/OL.44.002494 出版年: MAY 15 2019
摘要: A compact optic-fiber vector magnetometer is proposed and experimentally demonstrated, which is based on an excessively tilted fiber grating (Ex-TFG) assistant with the magnetic fluid (MF). Without any complicated processing, the cladding mode resonances of the bare Ex-TFG packaged by the MF show high sensitivity to slight perturbations by the magnetic field. Due to the excellent magneto-optical properties of the MF and the azimuth-dependent refractive index sensitivity of the Ex-TFG, such a magnetometer can achieve the magnetic field intensity sensitivity of 2.45 nm/mT and the orientation sensitivity of 0.41 nm/deg. In addition, based on the spectral interrogation, the detection limit of the magnetic field intensity could reach around 8.1 mu T at the minimum wavelength measurement accuracy of 0.02 nm. (C) 2019 Optical Society of America
入藏号: WOS:000467906400028
PubMed ID: 31090715
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Moreno, Yarien         W-4366-2019         

ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 167 条,共 344 条
标题: Graphene based polarization independent Fano resonance at terahertz for tunable sensing at nanoscale
作者: Wang, K (Wang, Kai); Fan, WH (Fan, Wen-Hui); Chen, X (Chen, Xu); Song, C (Song, Chao); Jiang, XQ (Jiang, Xiao-Qiang)
来源出版物: OPTICS COMMUNICATIONS 卷: 439 页: 61-65 DOI: 10.1016/j.optcom.2019.01.044 出版年: MAY 15 2019
摘要: A two-dimensional metamaterial structure consisting of polyimide layer covered by a square disk of monolayer graphene and the gold symmetrical split resonance ring is proposed and investigated. Our simulations indicate that the Fano resonance mode in the terahertz range can be generated by this metamaterial structure, and also utilized for nanoscale sensing. The maximum frequency shift is 1671.61 GHz, and the frequency sensitivity is 1.18 THz/RIU for 2-nm-thick analyte. Furthermore, by adjusting the Fermi level of graphene, the resonance frequency can be tuned actively. Different from the Fano resonance excited by asymmetric structure, the proposed structure is polarization-insensitive and can perform well with both TE and TM waves
入藏号: WOS:000460161400010
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 168 条,共 344 条
标题: Pulse signal restoration via stochastic resonance in a Fabry-Perot cavity with an intracavity nematic liquid crystal film
作者: Feng, XP (Feng, Xingpan); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu); Zhang, YB (Zhang, Yongbin)
来源出版物: OPTICS EXPRESS 卷: 27 期: 10 页: 14931-14941 DOI: 10.1364/OE.27.014931 出版年: MAY 13 2019
摘要: We theoretically propose a method to restore weak pulse signals submerged in noise via stochastic resonance, which is based on the optical bistability induced by the molecule reorientation in a Fabry-Perot cavity with an intracavity nematic liquid-crystal film. The bistable properties of this cavity are analyzed with different reflectance of the mirrors. initial phase shift and initial angle between the phase propagation vector and the director. The cross-correlation coefficient between pure input pulses and output is calculated to quantitatively evaluate the influence of noise intensity on output The simulation results show a cross-correlation gain of 3.2 and that the buried signal can be recovered effectively by this device. It proves the potential of using this structure to recover noise-hidden pulse signals in an all-optical system. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000469220500116
PubMed ID: 31163934
ISSN: 1094-4087
________________________________________
第 169 条,共 344 条
标题: Nanosecond level passively Q-switched Nd:YAG and Nd:YVO4 laser using black phosphorus as a saturable absorber
作者: Sun, Z (Sun, Zhe); Li, GY (Li, Guangying); Cheng, GH (Cheng, Guanghua); Wang, YG (Wang, Yonggang)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 13 文献号: 1950163 DOI: 10.1142/S021798491950163X 出版年: MAY 10 2019
摘要: Black phosphorus (BP) saturable absorber (SA) solution is fabricated by liquid-phase exfoliation method. By using the BP-SA solution, a compact diode-pumped passively Q-switched Nd:YAG and Nd:YVO4 laser has been demonstrated. 100 Hz and 1 kHz repetition rate pulse lasers are achieved, respectively. The minimum pulse duration is 3.56 ns. In the Q-switched Nd:YVO4 laser with wideband absorbers, the lowest repetition rate and the shortest pulse duration are obtained for the first time to the best of our knowledge. The maximum single pulse energy is as much as 0.1 mJ. Our results show that BP-SA solution can be developed as an effective SA to achieve nanosecond pulse laser.
入藏号: WOS:000468183400009
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 170 条,共 344 条
标题: Three-dimensional thermal model of high-power semiconductor lasers
作者: Wu, DH (Wu, Di-Hai); Zah, CE (Zah, Chung-En); Liu, XS (Liu, Xingsheng)
来源出版物: APPLIED OPTICS 卷: 58 期: 14 页: 3892-3901 DOI: 10.1364/AO.58.003892 出版年: MAY 10 2019
摘要: In this paper, 3-D, steady-state, analytical thermal models of high-power single-emitter semiconductor lasers (SEs) and laser diode arrays (LDAs) are derived, considering the heat conduction in multi-layered laser structures. Heat flow in the laser chips for an epi-down bonded SE and LDA is described using this model, and it is observed that the laser chips contribute to 8% and 6% of total heat dissipation for the SE and LDA, respectively. The submount size requirement for this model is discussed by revealing the heat flow in the submount. Through finite element simulations, the solution accuracy for the lasers with non-ideal submounts is confirmed. Finally, the performance of our proposed analytical models is verified by finite element simulations and experimental measurements based on the wavelength shift method. (C) 2019 Optical Society of America
入藏号: WOS:000467540700029
PubMed ID: 31158204
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wu, Di-Hai         U-9829-2018         0000-0001-8138-4242

ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 171 条,共 344 条
标题: High-Sensitivity and Long-Life Microchannel Plate Processed by Atomic Layer Deposition
作者: Cao, WW (Cao, Weiwei); Zhu, BL (Zhu, Bingli); Bai, XH (Bai, Xiaohong); Xu, P (Xu, Peng); Wang, B (Wang, Bo); Qin, JJ (Qin, Junjun); Gou, YS (Gou, Yongsheng); Lei, FP (Lei, Fanpu); Liu, BY (Liu, Baiyu); Guo, JJ (Guo, Junjiang); Zhu, JP (Zhu, Jingping); Bai, YL (Bai, Yonglin)
来源出版物: NANOSCALE RESEARCH LETTERS 卷: 14 文献号: 153 DOI: 10.1186/s11671-019-2983-1 出版年: MAY 6 2019
摘要: As a key component of electron multiplier device, a microchannel plate (MCP) can be applied in many scientific fields. Pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were deposited in the pores of MCP via atomic layer deposition (ALD) to overcome problems such as high dark current and low lifetime which often occur on traditional MCP. In this paper, we systematically investigate the morphology, element distribution, and structure of samples by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS), respectively. Output current of different thickness of Al2O3 was studied and an optimal thickness was found. Experimental tests show that the average gain of ALD-MCP was nearly five times better than that of traditional MCP, and the ALD-MCP showed better sensitivity and longer lifetime.
入藏号: WOS:000467135400001
PubMed ID: 31062184
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Cao, WeiWei                  0000-0001-6845-4963

ISSN: 1931-7573
eISSN: 1556-276X
________________________________________
第 172 条,共 344 条
标题: Process research on micro-machining diamond microgroove by femtosecond laser
作者: Dou, J (Dou, Jian); Sun, Y (Sun, Yu); Xu, MX (Xu, Muxun); Cui, JL (Cui, Jianlei); Mei, XS (Mei, Xuesong); Wang, WJ (Wang, Wenjun); Wang, XT (Wang, Xintian)
来源出版物: INTEGRATED FERROELECTRICS 卷: 198 期: 1 特刊: SI 页: 9-19 DOI: 10.1080/10584587.2019.1592571 出版年: MAY 4 2019
摘要: Using micro-nano processing system of 120 fs and 800 nm low-frequency femtosecond laser, the microgroove was processed on the CVD diamond. The effects of some processing parameters on the microgroove size were studied. The results showed that the depth and width of microgrooves increase with the increase of laser power, scanning times, while with the decrease of scanning speed. Moreover, the suitable scanning speed of femtosecond laser processing diamond is about 0.1 mm/s, and focusing on diamond can improve material removal efficiency and processing quality. It is indicated that these research work has certain guiding significance for processing diamond microchannels for heat dissipation of electronic chips.
入藏号: WOS:000476539400002
ISSN: 1058-4587
eISSN: 1607-8489
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第 173 条,共 344 条
标题: Ridge waveguides in magneto-optical glasses formed by combination of proton implantation and precise diamond blade dicing
作者: Zhu, QF (Zhu, Qi-Feng); Long, XW (Long, Xue-Wen); Wang, Y (Wang, Yue); Shen, XL (Shen, Xiao-Liang); Quo, HT (Quo, Hai-Tao); Fu, LL (Fu, Li-Li); Liu, CX (Liu, Chun-Xiao)
来源出版物: OPTICAL ENGINEERING 卷: 58 期: 5 文献号: 057107 DOI: 10.1117/1.OE.58.5.057107 出版年: MAY 2019
摘要: We report on the fabrication of a ridge waveguide in the Tb3+-doped aluminum borosilicate glass by combining the 550-keV proton implantation and the precise diamond blade dicing with a rotating speed of 20,000 rpm. The relative atom displacement of the original structure induced by the proton implantation is simulated by Stopping and Range of Ions in Matter 2013 in the Tb3+-doped aluminum borosilicate glass. The morphology of the ridge waveguide is acquired by scanning electron microscopy. The near-field intensity distribution of the waveguide is recorded by the end-face coupling system, which indicates that the light can be well confined in the ridge waveguide region. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE).
入藏号: WOS:000481889500053
ISSN: 0091-3286
eISSN: 1560-2303
________________________________________
第 174 条,共 344 条
标题: Spatiotemporal interest point detector exploiting appearance and motion-variation information
作者: Li, YS (Li, Yanshan); Li, QT (Li, Qingteng); Huang, QH (Huang, Qinghua); Xia, RJ (Xia, Rongjie); Li, XL (Li, Xuelong)
来源出版物: JOURNAL OF ELECTRONIC IMAGING 卷: 28 期: 3 文献号: 033002 DOI: 10.1117/1.JEI.28.3.033002 出版年: MAY 2019
摘要: As a local invariant feature of videos, the spatiotemporal interest point (STIP) has been widely used in computer vision and pattern recognition. However, existing STIP detectors are generally extended from detection algorithms constructed for local invariant features of two-dimensional images, which does not explicitly exploit the motion information inherent in the temporal domain of videos, thus weakening the performance of existing STIP detectors in a video context. To remedy this, we aim to develop an STIP detector that uniformly captures appearance and motion information for video, thus yielding substantial performance improvement. Specifically, under the framework of geometric algebra, we first develop a spatiotemporal unified model of appearance and motion-variation information (UMAMV), and then a UMAMV-based scale space of the spatiotemporal domain is proposed to synthetically analyze appearance information and motion information in a video. Based on this model, we propose an STIP feature of UMAMV-SIFT that embraces both appearance and motion variation information of the videos. Three datasets with different sizes are utilized to evaluate the proposed model and the STIP detector. We present experimental results to show that the UMAMV-SIFT achieves state-of-the-art performance and is particularly effective when dataset is small. (C) 2019 SPIE and IS&T
入藏号: WOS:000473732200002
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         

ISSN: 1017-9909
eISSN: 1560-229X
________________________________________
第 175 条,共 344 条
标题: A moving target extraction algorithm based on the fusion of infrared and visible images
作者: Qiu, S (Qiu, Shi); Luo, JS (Luo, Junsong); Yan, S (Yan, Song); Zhang, MY (Zhang, Meiyang); Zhang, W (Zhang, Wei)
来源出版物: INFRARED PHYSICS & TECHNOLOGY 卷: 98 页: 285-291 DOI: 10.1016/j.infrared.2019.03.022 出版年: MAY 2019
摘要: According to the principle of thermal imaging, moving targets can be better located in infrared images, but their boundary is blurred, and the details of objects cannot be displayed. The details of objects in natural images can be better shown, but for the condition of shelter, shadow and etc., miss-tracking and false-tracking may easily occur. Thus, we construct a framework for moving target extraction and tracking in infrared and natural images. For infrared images: according to the rough fuzzy set theory, we propose the rough entropy model based on the traditional frame difference method. The model is fused with the infrared imaging characteristics to locate moving target regions. For natural images: a time-space fusion LBP model is proposed for target coding. The model is integrated into the GMM model to obtain moving target information. The moving regions in infrared images and natural images are fused to form a priori model, and the C-V model is improved to extract targets accurately.
入藏号: WOS:000471361000035
ISSN: 1350-4495
eISSN: 1879-0275
________________________________________
第 176 条,共 344 条
标题: Analysis of Nitrate in Seawater of Wheat Island Based on LLE-BPNN
作者: Wang, XJ (Wang Xue-ji); Hu, BL (Hu Bing-liang); Yu, T (Yu Tao); Liu, QS (Liu Qing-song); Li, HB (Li Hong-bo); Fan, Y (Fan Yao)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS 卷: 39 期: 5 页: 1503-1508 DOI: 10.3964/j.issn.1000-0593(2019)05-1503-06 出版年: MAY 2019
摘要: Excessive nitrate in water may influence some aquatic organisms' survival and cause harm to humans, especially infants. Therefore, nitrate concentration becomes an important indicator in water quality monitoring. Due to the complexity of operation and slow response of conventional methods for measuring nitrate concentration, many researchers have begun to use ultraviolet/visible (UV-Vis) spectroscopy combined with artificial neural network (ANN) methods to measure nitrate content in water. This paper proposes a modeling method combining locally linear embedding (LLE) in manifold learning with back propagation neural network (BPNN). The relationship between the spectral curve of nitrate and the concentration was obtained, so that a rapid and accurate quantitative analysis of the nitrate concentration in the wheat island of Laoshan District, Qingdao was achieved. In the experiment, we selected 59 groups of spiked solutions with different concentrations of filtered wheat island seawater, and collected spectral measurements of these samples using a laboratory-developed spectrum analyzer, with standard normal variate (SNV) method calibrating spectral data of measured nitrate solution to reduce the noise caused by the instrument itself or the environment. First 1 500-dimensional of the pre-processed spectral data was used to avoid insufficient memory when using the entire 2 048-dimensional data to build BPNN model, and a control experiment was performed. Then the number of neighboring points k and the embedding dimension d in the LLE were optimized by the grid search combined with the ten-fold cross validation method, obtaining the optimal k = 15, d = 3. Then the dimension of the experimental data was reduced. The spectral information of the reduced-dimensional training set and its corresponding concentration information were modeled by the BPNN to achieve a quantitative analysis of the nitrate concentration in the prediction set. Coefficient of determination (R-2) and root mean square error of prediction (RMSEP) were introduced to evaluate modeling effects. And compared with the predicted results obtained by only using BPNN modeling, R-2 of our improved method increased from 0. 926 3 to 0. 992 8, and RMSEP decreased from 0. 442 5 to 0. 280 4, and prediction modeling program run time decreased from 327 s to about 0. 5 s. In addition, we used all 2 048 dimensions of the 59 data sets for LLE-BPNN modeling, with R-2 =0. 995 7 and RMSEP=0. 136 5, which was improved compared to the modeling accuracy when only using the first 1 500 dimensions, while elapsed time was similar. The analysis results above showed that using the LLE-BPNN method can achieve a rapid prediction of nitrate concentration in seawater, while significantly improving prediction accuracy and reducing prediction time.
入藏号: WOS:000469899500028
ISSN: 1000-0593
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第 177 条,共 344 条
标题: Hyperspectral Image Denoising by Fusing the Selected Related Bands
作者: Zheng, XT (Zheng, Xiangtao); Yuan, Y (Yuan, Yuan); Lu, XQ (Lu, Xiaoqiang)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 5 页: 2596-2609 DOI: 10.1109/TGRS.2018.2875304 出版年: MAY 2019
摘要: Hyperspectral images (HSIs) convey more useful information than RGB or gray images, which are widely used in many remote sensing tasks. In real scenarios, HSIs are inevitably corrupted by noise because of sensors' imperfectness or atmospheric influence. Recently, many HSI denoising methods have been proposed to utilize the interband information between different spectral bands. However, these methods regard the HSI as a whole and treat the different spectral bands with the same noise level. In fact, the noise levels in different bands are different. Especially, only few certain bands are corrupted by noise, named the target noised bands. Under this circumstance, an HSI denoising method is proposed by considering the band relationship and different noise levels. The target noised bands are adaptively denoised by fusing some selected bands. Specifically, some related but quality superior bands are selected according to the target noised bands. Then, the target noised bands can be denoised by fusing the selected related bands. Experimental results show that the proposed method achieves considerable performances in comparison with several state-of-the-art hyperspectral denoising methods.
入藏号: WOS:000466183500011
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 178 条,共 344 条
标题: Face Sketch Synthesis by Multidomain Adversarial Learning
作者: Zhang, SC (Zhang, Shengchuan); Ji, RR (Ji, Rongrong); Hu, J (Hu, Jie); Lu, XQ (Lu, Xiaoqiang); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 卷: 30 期: 5 页: 1419-1428 DOI: 10.1109/TNNLS.2018.2869574 出版年: MAY 2019
摘要: Given a training set of face photo-sketch pairs, face sketch synthesis targets at learning a mapping from the photo domain to the sketch domain. Despite the exciting progresses made in the literature, it retains as an open problem to synthesize high-quality sketches against blurs and deformations. Recent advances in generative adversarial training provide a new insight into face sketch synthesis, from which perspective the existing synthesis pipelines can be fundamentally revisited. In this paper, we present a novel face sketch synthesis method by multidomain adversarial learning (termed MDAL), which overcomes the defects of blurs and deformations toward high-quality synthesis. The principle of our scheme relies on the concept of "interpretation through synthesis." In particular, we first interpret face photographs in the photodomain and face sketches in the sketch domain by reconstructing themselves respectively via adversarial learning. We define the intermediate products in the reconstruction process as latent variables, which form a latent domain. Second, via adversarial learning, we make the distributions of latent variables being indistinguishable between the reconstruction process of the face photograph and that of the face sketch. Finally, given an input face photograph, the latent variable obtained by reconstructing this face photograph is applied for synthesizing the corresponding sketch. Quantitative comparisons to the state-of-the-art methods demonstrate the superiority of the proposed MDAL method.
入藏号: WOS:000466192100012
PubMed ID: 30281495
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 2162-237X
eISSN: 2162-2388
________________________________________
第 179 条,共 344 条
标题: Generalized Uncorrelated Regression with Adaptive Graph for Unsupervised Feature Selection
作者: Li, XL (Li, Xuelong); Zhang, H (Zhang, Han); Zhang, R (Zhang, Rui); Liu, Y (Liu, Yun); Nie, FP (Nie, Feiping)
来源出版物: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 卷: 30 期: 5 页: 1587-1595 DOI: 10.1109/TNNLS.2018.2868847 出版年: MAY 2019
摘要: Unsupervised feature selection always occupies a key position as a preprocessing in the tasks of classification or clustering due to the existence of extra essential features within high-dimensional data. Although lots of efforts have been made, the existing methods neglect to consider the redundancy of features, and thus select redundant features. In this brief, by virtue of a generalized uncorrelated constraint, we present an improved sparse regression model [generalized uncorrelated regression model (GURM)] for seeking the uncorrelated yet discriminative features. Benefited from this, the structure of data is kept in the Stiefel manifold, which avoids the potential trivial solution triggered by a conventional ridge regression model. Besides that, the uncorrelated constraint equips the model with the closed-form solution. In addition, we also incorporate a graph regularization term based on the principle of maximum entropy into the GURM model (URAFS), so as to embed the local geometric structure of data into the manifold learning. An efficient algorithm is designed to perform URAFS by virtue of the existing generalized powered iteration method. Extensive experiments on eight benchmark data sets among seven state-of-the-art methods on the task of clustering are conducted to verify the effectiveness and superiority of the proposed method.
入藏号: WOS:000466192100027
PubMed ID: 30281488
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Nie, Feiping         B-3039-2012         
Nie, Feiping                  0000-0002-0871-6519
Zhang, Rui         U-4639-2017         0000-0001-9418-0863

ISSN: 2162-237X
eISSN: 2162-2388
________________________________________
第 180 条,共 344 条
标题: Improved vector-extrapolation-based Richardson-Lucy algorithm used for wavefront coded imaging
作者: Zhao, H (Zhao, Hui); Xia, JJ (Xia, JingJing); Zhang, L (Zhang, Ling); Fan, XW (Fan, Xuewu)
来源出版物: APPLIED OPTICS 卷: 58 期: 13 页: 3630-3638 DOI: 10.1364/AO.58.003630 出版年: MAY 1 2019
摘要: The Richardson-Lucy (RL) algorithm is a well-known nonlinear restoration method and has been widely applied in the fields of astronomical image restoration, microscopic image restoration, and so on because of its capability of generating high-quality restoration results and potential in realizing super-resolution. However, when being applied to restore the wavefront coded blurry images, the classical RL algorithm converges very slowly and has to be iterated many times before obtaining a satisfactory result, which severely prohibits its real-time application. Vector-extrapolation-based RL algorithm was invented to solve this problem, but the noise amplification increases fast, and additional post-processing is needed to further improve the signal-to-noise ratio. Therefore, in this paper, an improved RL algorithm is proposed by introducing an exponential modified correction term into the framework of the original vector-extrapolation-based RL algorithm. It not only results in a bigger iteration step, which ensures a faster convergence can be obtained, but also the noise amplification is effectively prohibited. Besides that, we design a structure-similarity-index-metric-based stopping criterion, based on which the optimum number of iterations for each color channel is obtained. Experimental results reveal that the total iterations decreases approximately 78.9%, and the restored images demonstrate a superior visual quality without denoising additionally. (C) 2019 Optical Society of America
入藏号: WOS:000467539700055
PubMed ID: 31044865
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 181 条,共 344 条
标题: Automated Fine Motor Evaluation for Developmental Coordination Disorder
作者: Li, RM (Li, Ruimin); Fu, H (Fu, Hong); Zheng, Y (Zheng, Yang); Lo, WL (Lo, Wai-Lun); Yu, JJ (Yu, Jane J.); Sit, CHP (Sit, Cindy H. P.); Chi, ZR (Chi, Zheru); Song, ZX (Song, Zongxi); Wen, DS (Wen, Desheng)
来源出版物: IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING 卷: 27 期: 5 页: 963-973 DOI: 10.1109/TNSRE.2019.2911303 出版年: MAY 2019
摘要: Developmental coordination disorder (DCD) is a type of motor learning difficulty that affects five to six percent of school-aged children, which may have a negative impact on the life of the sufferers. Timely and objective diagnosis of DCD are important for the success of the intervention. The present evaluation methods of DCD rely heavily on the observational analysis of occupational therapists and physiotherapists, who score the performance when children conduct some designed tasks. However, these methods are expensive, subjective, and are not easy to expand to a larger population. A fine motor evaluation system (FMES) is proposed with two views of cameras to record children's performance, when they carry out three fine motor tasks. Automated algorithms are developed to perform automated scoring of fine motor skill. The automated algorithms include task localization and individual task evaluation. The purpose of task localization is to detect each task and extract segments belonging to each task from the original video that includes multiple segments of different tasks. A convolutional neural network with temporal filtering is used to do frame-wise classification, and a boundary localization algorithm is proposed to localize each task segment. For individual task evaluation, the extracted video segments of task 1 and task 2 are evaluated based on the proposed feature extraction and time positioning algorithm, and the paper drawings of task 3 are evaluated based on image processing. The proposed methods are validated on a diverse population of children with or without DCD by comparing automated scoring with manual scoring from a professional evaluator. The experimental results suggest that the proposed methods can effectively achieve fine motor evaluation for DCD assessment. Besides, our system is a low-cost solution, and the evaluation methods developed are automated, objective, and can be suited for large population evaluation and analysis.
入藏号: WOS:000467572900019
PubMed ID: 30998471
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
LI, RUIMIN         AAG-6616-2019         0000-0003-2393-2225

ISSN: 1534-4320
eISSN: 1558-0210
________________________________________
第 182 条,共 344 条
标题: High-speed focusing and scanning light through a multimode fiber based on binary amplitude-only modulation parallel coordinate algorithm
作者: Geng, Y (Geng, Yi); Zhao, GZ (Zhao, Guangzhi); Chen, H (Chen, Hui); Xu, CF (Xu, Chengfang); Zhuang, B (Zhuang, Bin); Ren, LY (Ren, Liyong)
来源出版物: APPLIED PHYSICS B-LASERS AND OPTICS 卷: 125 期: 5 文献号: 83 DOI: 10.1007/s00340-019-7197-9 出版年: MAY 2019
摘要: In this paper, we present a binary amplitude-only modulation parallel coordinate algorithm for focusing and scanning light through a multimode fiber (MMF) based on the digital micro-mirror device (DMD) in a reference-free multimode fiber imaging system. In principle, our algorithm is capable of efficiently calculating the masks to be added to DMD for yielding a series of tightly focused spots; and for the same number of modulation sub-regions, our method is more than M (the number of focused spots) times faster than the amplitude iterative optimization algorithm. In the experiment, efficient light focusing and scanning at the distal end of the MMF are demonstrated. Furthermore, we demonstrate that the proposed method can also be extended to focus and scan light at multiple planes along the axial direction by just modifying the input wavefront accordingly; and our algorithm can be applied not only in multimode optical fiber focusing but also to other disordered media. Particularly, it will be valuable in fast multimode fiber calibration for endoscopic imaging.
入藏号: WOS:000466283900002
ISSN: 0946-2171
eISSN: 1432-0649
________________________________________
第 183 条,共 344 条
标题: Electrically tunable temporal imaging in a graphene-based waveguide
作者: Xie, P (Xie, Peng); Wen, Y (Wen, Yu); Wan, ZS (Wan, Zishen); Wang, XY (Wang, Xinyu); Liu, JR (Liu, Jiarui); Yang, WD (Yang, Wendiang); Li, XF (Li, Xiaofeng); Wang, YS (Wang, Yishan)
来源出版物: JAPANESE JOURNAL OF APPLIED PHYSICS 卷: 58 期: 5 文献号: 050914 DOI: 10.7567/1347-4065/ab0c52 出版年: MAY 1 2019
摘要: We propose an electrically tunable temporal imaging system (TIS) based on four-wave mixing in a dispersion engineered graphene-based waveguide, which could realize a magnification factor of 1000 x for a signal consisting of two 100-fs-wide pulses separated by 500 fs and a large working bandwidth of about 700 nm. The TIS was analyzed by solving the couple-mode equations in detail. It was demonstrated that the working wavelength range could be tuned via a small disturbed bias voltage applied to the graphene layer without changing the geometric structure of the waveguide. These results provide attractive insights for potential applications in integrated optics and optical communications. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000464999700004
ISSN: 0021-4922
eISSN: 1347-4065
________________________________________
第 184 条,共 344 条
标题: Fabrication and characterization of a polymeric curved compound eye
作者: Wang, YY (Wang, Yuanyuan); Shi, CY (Shi, Chengyong); Liu, CY (Liu, Chenyang); Yu, XD (Yu, Xiaodan); Xu, HR (Xu, Huangrong); Wang, TS (Wang, Taisheng); Qiao, YF (Qiao, Yanfeng); Yu, WX (Yu, Weixing)
来源出版物: JOURNAL OF MICROMECHANICS AND MICROENGINEERING 卷: 29 期: 5 文献号: 055008 DOI: 10.1088/1361-6439/ab0e9f 出版年: MAY 2019
摘要: Curved compound eyes, i.e. microlens arrays on curved surfaces, are highly desirable for their unique optical properties including wide field of view, tracking of fast moving objects and so on. However, it is technically challenging to fabricate biomimetic gapless microlens arrays. In this work, we report a simple method for fabricating close-packed microlenses in a kind of stretchable polymeric material PDMS on curved surfaces inspired by the vertebrate eyes. The successfully fabricated polymeric curved compound eye consists of more than 6000 closepacked ommatidia with an average diameter of 600 mu m for each ommatidium. The ommatidia are located on a convex surface with a diameter of 40mm and thus a total field of view of about 180 degrees has been obtained. The optical test on ommatidia shows that the NA for each ommatidium is about 0.21 and the imaging result of the whole compound eye is also given. Furthermore, an optical relay system is introduced to integrate with the compound eye to form a biomimetic compound eye camera. The formed camera is shown to have a great potential for a broad range of optical imaging applications, such as surveillance imaging, target detection and tracking, surveying and mapping, collision-free navigation of terrestrial and aerospace vehicles.
入藏号: WOS:000463547700001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yu, Weixing         G-3658-2012         0000-0002-3216-526X

ISSN: 0960-1317
eISSN: 1361-6439
________________________________________
第 185 条,共 344 条
标题: All-fiber polarization interference filter based uniform multiwavelength erbium-doped fiber laser
作者: Wang, HS (Wang, Hushan); Zhao, FY (Zhao, Fengyan); Yan, ZJ (Yan, Zhijun); Hong, XH (Hong, Xiaohu); Song, JZ (Song, Jiazheng); Zhou, KM (Zhou, Kaiming); Zhang, T (Zhang, Ting); Zhang, W (Zhang, Wei); Wang, YS (Wang, Yishan)
来源出版物: LASER PHYSICS 卷: 29 期: 5 文献号: 055105 DOI: 10.1088/1555-6611/ab0d0e 出版年: MAY 2019
摘要: We demonstrate a compact and stable room-temperature multiwavelength erbium doped fiber laser by employing 45 degrees tilted fiber gratings based on an all-fiber polarization interference filter. Benefiting from the filter, the channel number, linewidth, uniformity and stabilization of the multiwavelength laser are greatly improved. The filter also works as a functional polarizing device in a nonlinear polarization rotation, leading to the multiwavelength operation. Instead of a highly nonlinear fiber, the single mode fiber is used to provide enough linearity and to reduce the splice loss. More than 80 wavelengths (within a 3 dB bandwidth), lasing with a linewidth of 0.03 nm and a signal-to-noise ratio of 33 dB, are obtained. The wavelength spacing of 0.164 nm agrees with the channel spacing of the filter, and can be flexibly controlled by adjusting the length of the filter.
入藏号: WOS:000463555400001
ISSN: 1054-660X
eISSN: 1555-6611
________________________________________
第 186 条,共 344 条
标题: WS(2 )Passively Q-switched Er:SrF2 Laser at similar to 3 mu m
作者: Xu, JH (Xu, Jihua); Li, M (Li, Ming); Chen, YQ (Chen, Yinqi)
来源出版物: LASER PHYSICS 卷: 29 期: 5 文献号: 055802 DOI: 10.1088/1555-6611/aaf325 出版年: MAY 2019
摘要: A few-layer tungsten disulfide (WS2) nanosheet film on a YAG substrate was fabricated and used as saturable absorber in a passively Q-switched Er:SrF2 laser operating at 2.79 mu m. Under an absorbed power of 2.42 W, a stable Q-switched laser operation was realized with an average output power of 428 mW and a pulse duration of 679 ns at a repetition rate of 38 kHz, corresponding to a pulse energy of 11.26 mu J.
入藏号: WOS:000462620000002
ISSN: 1054-660X
eISSN: 1555-6611
________________________________________
第 187 条,共 344 条
标题: A Hybrid Level Set With Semantic Shape Constraint for Object Segmentation
作者: Wang, B (Wang, Bin); Yuan, XY (Yuan, Xiuying); Gao, XB (Gao, Xinbo); Li, XL (Li, Xuelong); Tao, DC (Tao, Dacheng)
来源出版物: IEEE TRANSACTIONS ON CYBERNETICS 卷: 49 期: 5 页: 1558-1569 DOI: 10.1109/TCYB.2018.2799999 出版年: MAY 2019
摘要: This paper presents a hybrid level set method for object segmentation. The method deconstructs segmentation task into two procedures, i.e., shape transformation and curve evolution, which are alternately optimized until convergence. In this framework, only one shape prior encoded by shape context is utilized to estimate a transformation allowing the curve to have the same semantic expression as shape prior, and curve evolution is driven by an energy functional with topology-preserving and kernelized terms. In such a way, the proposed method is featured by the following advantages: 1) hybrid paradigm makes the level set framework possess the ability of incorporating other shape-related techniques about shape descriptor and distance; 2) shape context endows one single prior with semanticity, and hence leads to the competitive performance compared to the ones with multiple shape priors; and 3) additionally, combining topology-preserving and kernelization mechanisms together contributes to realizing a more reasonable segmentation on textured and noisy images. As far as we know, we propose a hybrid level set framework and utilize shape context to guide curve evolution for the first time. Our method is evaluated with synthetic, healthcare, and natural images, as a result, it shows competitive and even better performance compared to the counterparts.
入藏号: WOS:000460667400001
PubMed ID: 29994789
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Wang, Bin         M-9701-2019         0000-0003-1118-3618
Li, Xuelong                  0000-0002-0019-4197

ISSN: 2168-2267
eISSN: 2168-2275
________________________________________
第 188 条,共 344 条
标题: Low-Rank 2-D Neighborhood Preserving Projection for Enhanced Robust Image Representation
作者: Lu, YW (Lu, Yuwu); Lai, ZH (Lai, Zhihui); Li, XL (Li, Xuelong); Wong, WK (Wong, Wai Keung); Yuan, C (Yuan, Chun); Zhang, D (Zhang, David)
来源出版物: IEEE TRANSACTIONS ON CYBERNETICS 卷: 49 期: 5 页: 1859-1872 DOI: 10.1109/TCYB.2018.2815559 出版年: MAY 2019
摘要: 2-D neighborhood preserving projection (2DNPP) uses 2-D images as feature input instead of 1-D vectors used by neighborhood preserving projection (NPP). 2DNPP requires less computation time than NPP. However, both NPP and 2DNPP use the L2 norm as a metric, which is sensitive to noise in data. In this paper, we proposed a novel NPP method called low-rank 2DNPP (LR-2DNPP). This method divided the input data into a component part that encoded low-rank features, and an error part that ensured the noise was sparse. Then, a nearest neighbor graph was learned from the clean data using the same procedure as 2DNPP. To ensure that the features learned by LR-2DNPP were optimal for classification, we combined the structurally incoherent learning and low-rank learning with NPP to form a unified model called discriminative LR-2DNPP (DLR-2DNPP). By encoding the structural incoherence of the learned clean data, DLR-2DNPP could enhance the discriminative ability for feature extraction. Theoretical analyses on the convergence and computational complexity of LR-2DNPP and DLR-2DNPP were presented in details. We used seven public image databases to verify the performance of the proposed methods. The experimental results showed the effectiveness of our methods for robust image representation.
入藏号: WOS:000460667400026
PubMed ID: 29994294
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lai, Zhihui         R-1000-2019         0000-0002-4388-3080
Li, Xuelong         Z-3785-2019         
Li, Xuelong                  0000-0002-0019-4197
Wong, Wai Keung                  0000-0002-5214-7114

ISSN: 2168-2267
eISSN: 2168-2275
________________________________________
第 189 条,共 344 条
标题: Multi-component yttrium aluminosilicate (YAS) fiber prepared by melt-in-tube method for stable single-frequency laser
作者: Zhang, YM (Zhang, Yeming); Wang, WW (Wang, Weiwei); Li, J (Li, Jiang); Xiao, XS (Xiao, Xusheng); Ma, ZJ (Ma, Zhijun); Guo, HT (Guo, Haitao); Dong, GP (Dong, Guoping); Xu, SH (Xu, Shanhui); Qiu, JR (Qiu, Jianrong)
来源出版物: JOURNAL OF THE AMERICAN CERAMIC SOCIETY 卷: 102 期: 5 页: 2551-2557 DOI: 10.1111/jace.16072 出版年: MAY 2019
摘要: The multi-component glass fibers have demonstrated their unique advantages in the application of single-frequency lasers due to their higher solubility of rare-earth ions and thus a higher gain per unit length in a compact fiber laser cavity. In this study, multi-component yttrium aluminosilicate (YAS) fiber with high doping concentration of Yb3+ was prepared by the "melt-in-tube" (MIT) method. A unit-length gain of 3 dB/cm was obtained in a 4.4 cm-long YAS fiber, the laser output slope efficiency reached 23.8% in a 10 cm-long Yb:YAS fiber. Single-frequency laser operation was achieved in a 1.7-cm-long Yb:YAS active fiber. To the best of our knowledge, this is the first demonstration of single-frequency laser with this YAS glass fiber as gain medium. The novel multi-component YAS fiber can be applied as a new gain material to realize single-frequency fiber laser.
入藏号: WOS:000460080000030
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
li, jiang                  0000-0002-4541-4886

ISSN: 0002-7820
eISSN: 1551-2916
________________________________________
第 190 条,共 344 条
标题: Single-shot spatiotemporal intensity measurement of picosecond laser pulses with compressed ultrafast photography
作者: Cao, FY (Cao, Fengyan); Yang, CS (Yang, Chengshuai); Qi, DL (Qi, Dalong); Yao, JL (Yao, Jiali); He, YL (He, Yilin); Wang, X (Wang, Xing); Wen, WL (Wen, Wenlong); Tian, JS (Tian, Jinshou); Jia, TQ (Jia, Tianqing); Sun, ZR (Sun, Zhenrong); Zhang, S (Zhang, Shian)
来源出版物: OPTICS AND LASERS IN ENGINEERING 卷: 116 页: 89-93 DOI: 10.1016/j.optlaseng.2019.01.002 出版年: MAY 2019
摘要: The spatiotemporal measurement of the ultrashort laser pulses is of great significance in the diagnosis of the instrument performance and the exploration of the laser and matter interaction. In this work, we report an advanced compressed ultrafast photography (CUP) technique to measure the spatiotemporal intensity distribution of the picosecond laser pulses with a single shot. This CUP technique is based on a three-dimensional image reconstruction strategy by employing the random codes to encode the space-time-evolving laser pulse and decode it based on a compressed sensing (CS) algorithm. In our CUP system, the measurable laser wavelength depends on the spectral response of the streak camera, which can cover a wide range from ultraviolet (200 nm) to near infrared (850 nm). Based on the CUP system we develop, we successfully measure the spatiotemporal intensity evolutions of some typical laser pulses, such as the 800 nm picosecond laser pulse, the 800 and 400 nm two-color picosecond laser pulses and the supercontinuum picosecond laser pulse. These experimental results show that the CUP technique can well characterize the spatiotemporal intensity information of the picosecond laser pulses. Moreover, this technique has the remarkable advantages with the single shot measurement and without the reference laser pulse.
入藏号: WOS:000458939400012
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Cao, Fengyan                  0000-0001-6292-5509

ISSN: 0143-8166
eISSN: 1873-0302
________________________________________
第 191 条,共 344 条
标题: Underwater polarimetric imaging for visibility enhancement utilizing active unpolarized illumination
作者: Yang, LM (Yang, Liming); Liang, J (Liang, Jian); Zhang, WF (Zhang, Wenfei); Ju, HJ (Ju, Haijuan); Ren, LY (Ren, Liyong); Shao, XP (Shao, Xiaopeng)
来源出版物: OPTICS COMMUNICATIONS 卷: 438 页: 96-101 DOI: 10.1016/j.optcom.2018.12.022 出版年: MAY 1 2019
摘要: Underwater imaging is attractive but challenging. Images could be severely degraded by the particles in turbid water because of backscatter generation and signal light attenuation. In this paper, we focus on the scheme of underwater imaging and study the methods of visibility enhancement of turbid underwater images based on polarimetric imaging utilizing active unpolarized illumination. Compared with traditional polarimetric imaging using linearly polarized illumination, using unpolarized illumination ensures the polarization effect of the signal light could be neglected, no matter the depolarization degree of the object is high or low, which expands the application range of underwater polarimetric imaging and makes the underwater polarimetric imaging scheme more reliable and robust. Experimentally, the visibility and the contrast of underwater images are enhanced effectively. In addition, it is demonstrated that our method is applicable for objects of different materials and different imaging distances in turbid water. The contrast of underwater images could be promoted at least 100%, meaning that this kind of technique can be potentially used in many underwater environments.
入藏号: WOS:000458517100015
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 192 条,共 344 条
标题: Joint Learning of Fuzzy k-Means and Nonnegative Spectral Clustering With Side Information
作者: Zhang, R (Zhang, Rui); Nie, FP (Nie, Feiping); Guo, MH (Guo, Muhan); Wei, X (Wei, Xian); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON IMAGE PROCESSING 卷: 28 期: 5 页: 2152-2162 DOI: 10.1109/TIP.2018.2882925 出版年: MAY 2019
摘要: As one of the most widely used clustering techniques, the fuzzy k-means (FKM) assigns every data point to each cluster with a certain degree of membership. However, conventional FKM approach relies on the square data fitting term, which is sensitive to the outliers with ignoring the prior information. In this paper, we develop a novel and robust fuzzy k-means clustering algorithm, namely, joint learning of fuzzy k-means and nonnegative spectral clustering with side information. The proposed method combines fuzzy k-means and nonnegative spectral clustering into a unified model, which can further exploit the prior knowledge of data pairs such that both the quality of affinity graph and the clustering performance can be improved. In addition, for the purpose of enhancing the robustness, the adaptive loss function is adopted in the objective function, since it smoothly interpolates between l(1)-norm and l(2)-norm. Finally, experimental results on benchmark datasets verify the effectiveness and the superiority of our clustering method.
入藏号: WOS:000456542000005
PubMed ID: 30475719
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Nie, Feiping         B-3039-2012         
Li, Xuelong         Z-3785-2019         
Nie, Feiping                  0000-0002-0871-6519
Zhang, Rui         U-4639-2017         0000-0001-9418-0863

ISSN: 1057-7149
eISSN: 1941-0042
________________________________________
第 193 条,共 344 条
标题: Optical design and laboratory test of an internal pushbroom hyperspectral microscopy
作者: Zhang, ZF (Zhang, Zhoufeng); Hu, BL (Hu, Bingliang); Yin, QY (Yin, Qinye); Yu, T (Yu, Tao); Zhang, ZH (Zhang, Zhaohui)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 12 文献号: UNSP 1950143 DOI: 10.1142/S0217984919501434 出版年: APR 30 2019
摘要: Hyperspectral imaging is an emerging technology for various medical applications, especially in disease diagnosis of early and biomedical research based on their unique spectral signatures. A hyperspectral microscopy based on a prism-grating-prism is designed for various medical applications. The spectral range between 400 nm to 800 nm is sampled by 256 spectral channels, the modulation transfer function (MTF) values of full spectrum and full field of view are close to the diffraction limit, the smile is less than 6.4% of a pixel, and the keystone is less than 1.6% of a pixel. At the same time, the hyperspectral microscopy used an internal pushbroom technology, which has the advantages of compact structure and good portability. The spectral imaging results demonstrate the great potential of this internal pushbroom hyperspectral microscopy for the pathologists to automatically detect tumor tissue in pathological slides and early disease diagnosis.
入藏号: WOS:000466875800003
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 194 条,共 344 条
标题: Single-wavelength-tunable and dual-wavelength-switchable Tm-doped fiber soliton laser based on single-walled carbon nanotubes
作者: Li, WL (Li, Wenlei); Chen, GW (Chen, Guangwei)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 11 文献号: 1950136 DOI: 10.1142/S0217984919501367 出版年: APR 20 2019
摘要: We propose a single-wavelength-tunable and dual-wavelength-switchable Tm-doped fiber soliton laser with single-walled carbon nanotubes. The laser can deliver single-wavelength mode-locked pulse tunable from 1892 nm to 1924 nm. Dual-wavelength mode-locking operation can also be achieved by increasing pump power and rotating the polarization controller (PC), meanwhile the wavelength can be switched between 1883/1894 nm and 1905/1910 nm. Both the tunable and switchable operations are realized with great ease by solely adjusting the parameters of PC. The proposed Tm-doped fiber laser can operate in two mode-locking states, which is helpful for further understanding of the mode-locking mechanism and useful for practical applications.
入藏号: WOS:000465202800010
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 195 条,共 344 条
标题: Integrating temporal and spatial control of electronic transitions for bright multiphoton upconversion
作者: Sun, TY (Sun, Tianying); Li, YH (Li, Yuhua); Ho, WL (Ho, Wai Lok); Zhu, Q (Zhu, Qi); Chen, X (Chen, Xian); Jin, LM (Jin, Limin); Zhu, HM (Zhu, Haomiao); Huang, BL (Huang, Bolong); Lin, J (Lin, Jun); Little, BE (Little, Brent E.); Chu, ST (Chu, Sai Tak); Wang, F (Wang, Feng)
来源出版物: NATURE COMMUNICATIONS 卷: 10 文献号: 1811 DOI: 10.1038/s41467-019-09850-2 出版年: APR 18 2019
摘要: The applications of lanthanide-doped upconversion nanomaterials are limited by unsatisfactory brightness currently. Herein, a general strategy is proposed for boosting the upconversion efficiency in Er3+ ions, based on combined use of a core-shell nanostructured host and an integrated optical waveguide circuit excitation platform. A NaErF4@NaYF4 core-shell nanoparticle is constructed to host the upconversion process for minimizing non-radiative dissipation of excitation energy by surface quenchers. Furthermore, an integrated optical microring resonator is designed to promote absorption of excitation light by the nanoparticles, which alleviates quenching of excited states due to cross-relaxation and phonon-assisted energy transfer. As a result, multiphoton upconversion emission with a large anti-Stokes shift (greater than 1150 nm) and a high energy conversion efficiency (over 5.0%) is achieved under excitation at 1550 nm. These advances in controlling photon upconversion offer exciting opportunities for important photonics applications.
入藏号: WOS:000464979600005
PubMed ID: 31000711
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
Feng, Wang         E-2436-2013         0000-0001-9471-4386
Lin, Jun         D-3750-2012         
Huang, Bolong         AAG-5165-2019         0000-0002-2526-2002
ZHU, Qi                  0000-0002-9413-9120
LI, Yuhua                  0000-0003-2402-3234

ISSN: 2041-1723
________________________________________
第 196 条,共 344 条
标题: Linear space-variant optical cryptosystem via Fourier ptychography
作者: Pan, A (Pan, An); Wen, K (Wen, Kai); Yao, BL (Yao, Baoli)
来源出版物: OPTICS LETTERS 卷: 44 期: 8 页: 2032-2035 DOI: 10.1364/OL.44.002032 出版年: APR 15 2019
摘要: An optical cryptosystem via Fourier ptychography with double random phase masks is proposed. The encryption process cannot be precisely simulated except by optical experiment due to vignetting, which is space variant and can act as a one-way function from the perspective of pure optics and improve the security of our system. In addition, the encryption for a high-resolution, large field-of-view, and complex-valued image is achievable. Optical experiments are presented to prove the validity and security of the proposed system. Our method will give more insight into separating optical cryptography from computer cryptography in nature. (C) 2019 Optical Society of America
入藏号: WOS:000464601900038
PubMed ID: 30985803
ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 197 条,共 344 条
标题: Numerical study and test of the APS linac transverse deflecting cavity
作者: Hui, D (Hui, D.); Sun, Y (Sun, Y.); Smith, T (Smith, T.); Luo, D (Luo, D.); Yao, CY (Yao, C-Y); Tian, J (Tian, J.)
来源出版物: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 卷: 923 页: 118-126 DOI:10.1016/j.nima.2019.01.043 出版年: APR 11 2019
摘要: The transverse deflecting cavity can be used to transform particle distributions in the 6D phase space, which makes it a promising component in phase space beam diagnostics and beam manipulations. In the Advanced Photon Source (APS) Linac, a LOLA-type traveling wave deflecting cavity was installed for the diagnostics of beam characteristics, such as the bunch length, bunch temporal profile, time-dependent energy spread and slice (time-correlated) transverse emittance. In this paper, this deflecting cavity is modeled and analyzed with the numerical method. The effects of the center cell and coupler cell dimensions on the performance of the whole structure are studied, which shows the coupler cell radius has a dominant effect over the coupler cell length and slot width on the global reflection coefficient and field flatness. Important RF parameters, such as S-11, field flatness and phase advance etc., of the LOLA-II cavity in tuning are calculated and discussed. After optimization, the field flatness of the cavity is 2.1%, the phase advance is 119.66 degrees degrees with a standard deviation smaller than 0.5 degrees and the bandwidth is 15.738 MHz when VSWR < 1.1 (i.e. the S-11, < -26 dB). Bead-pull measurements and RF conditioning have been also performed and discussed. Finally, the initial cavity commissioning with electron beam of 375 MeV is reported, and compared with simulation.
入藏号: WOS:000459034800018
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Luo, Duan                  0000-0001-5926-9870

ISSN: 0168-9002
eISSN: 1872-9576
________________________________________
第 198 条,共 344 条
标题: Rapid wide-field imaging through scattering media by digital holographic wavefront correction
作者: Li, RZ (Li, Runze); Peng, T (Peng, Tong); Zhou, ML (Zhou, Meiling); Yu, XH (Yu, Xianghua); Gao, P (Gao, Peng); Min, JW (Min, Junwei); Yang, YL (Yang, Yanlong); Lei, M (Lei, Ming); Yao, BL (Yao, Baoli); Zhang, CM (Zhang, Chunmin); Ye, T (Ye, Tong)
来源出版物: APPLIED OPTICS 卷: 58 期: 11 页: 2845-2853 DOI: 10.1364/AO.58.002845 出版年: APR 10 2019
摘要: Imaging through scattering media has been a long standing challenge in many disciplines. One of the promising solutions to address the challenge is the wavefront shaping technique, in which the phase distortion due to a scattering medium is corrected by a phase modulation device such as a spatial light modulator (SLM). However, the wide-field imaging speed is limited either by the feedback-based optimization to search the correction phase or by the update rate of SLMs. In this report, we introduce a new method called digital holographic wavefront correction, in which the correction phase is determined by a single-shot off-axis holography. The correction phase establishes the so-called "scattering lens", which allows any objects to be imaged through scattering media; in our case, the "scattering lens" is a digital one established through computational methods. As no SLM is involved in the imaging process, the imaging speed is significantly improved. We have demonstrated that moving objects behind scattering media can be recorded at the speed of 2.8 fps with each frame corrected by the updated correction phase while the image contrast is maintained as high as 0.9. The image speed can potentially reach the video rate if the computing power is sufficiently high. We have also demonstrated that the digital wavefront correction method also works when the light intensity is low, which implicates its potential usefulness in imaging dynamic processes in biological tissues. (C) 2019 Optical Society of America
入藏号: WOS:000464007800014
PubMed ID: 31044887
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Peng, Tong                  0000-0003-0373-5136
Yu, Xianghua                  0000-0002-7447-1396

ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 199 条,共 344 条
标题: The Near-Space Wind and Temperature Sensing Interferometer: Forward Model and Measurement Simulation
作者: He, WW (He, Weiwei); Wu, KJ (Wu, Kuijun); Feng, YT (Feng, Yutao); Fu, D (Fu, Di); Chen, ZW (Chen, Zhenwei); Li, FQ (Li, Faquan)
来源出版物: REMOTE SENSING 卷: 11 期: 8 文献号: 914 DOI: 10.3390/rs11080914 出版年: APR 2 2019
摘要: Wind and temperature observation in near space has been playing an increasingly important role in atmospheric physics and space science. This paper reports on the near-space wind and temperature sensing interferometer (NWTSI), which employs a wide-angle Michelson interferometer to observe O-2(a(g)(1)) dayglow near 1.27 m from a limb-viewing satellite, and presents the instrument modeling and observation simulations from the stratosphere to the mesosphere and lower thermosphere. The characteristics of atmospheric limb-radiance spectra and line selection rules are described. The observational strategy of using two sets of three emission lines with a line-strength difference of one order of magnitude is proved to be suitable for extending altitude coverage. The forward modeling and measurement simulation of the expected NWTSI observations are provided, and the measurement uncertainty of the wind and temperature is discussed. The signal-to-noise ratio (SNR) and the limb-view weight work together to affect the precision of the wind and temperature measurements. The simulated results indicate a wind measurement precision of 1 to 3 m/s and a temperature precision of 1 to 3 K over an altitude range from 40 to 80 km, which meets the observing requirement in measurement precision for near-space detection.
入藏号: WOS:000467646800024
ISSN: 2072-4292
________________________________________
第 200 条,共 344 条
标题: Compact, robust, and repetition-rate-locked all-polarization-maintaining femtosecond fiber laser system
作者: Cai, YJ (Cai, Yajun); Pan, R (Pan, Ran); Zhang, T (Zhang, Tong); Liu, YS (Liu, Yuanshan); Wang, HS (Wang, Hushan); Zhang, W (Zhang, Wei); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Feng, Y (Feng, Ye); Hu, XH (Hu, Xiaohong)
来源出版物: OPTICAL ENGINEERING 卷: 58 期: 4 文献号: 046108 DOI: 10.1117/1.OE.58.4.046108 出版年: APR 2019
摘要: We demonstrate a 200-MHz all polarization-maintaining, repetition-rate-locked femtosecond fiber laser system with a total electrical power consumption of 11 W. The center wavelength, spectral width, pulse width, and average output power of the laser are 1558.8 nm, 34 nm, 139 fs, and 77.6 mW, respectively. The proposed laser system that integrates all optical components and locking electronics has a volume less than 1.5 L, a mass of 1.3 kg, and a fast locking time of 3 s (from the free running state to the repetition-rate-locked state). Using a hydrogen maser as the frequency reference, after locking, the Allan deviation is 2.8 mHz at a gate time of 1 s. Further, we place the repetition-rate-locked fiber laser system on a homemade shaker table with peak and rms accelerations of 1.97 and 0.7 g, respectively; the experimental results show that the locking state can be maintained robustly with Allan deviation of 2.0 mHz. The highly integrated, robust fiber laser system has potential applications in the areas of ultralow-noise microwave generation and high-precision distance measurement in outdoor environments. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE).
入藏号: WOS:000481889000034
ISSN: 0091-3286
eISSN: 1560-2303
第 201 条,共 344 条
标题: Optical system design of four-channel dual-band infrared panoramic imaging
作者: Gao, M (Gao Ming); Chen, Y (Chen Yang); Zhang, XB (Zhang Xibin)
来源出版物: OPTICAL ENGINEERING 卷: 58 期: 4 文献号: 045104 DOI: 10.1117/1.OE.58.4.045104 出版年: APR 2019
摘要: In order to reduce the volume of a panoramic optical system, a four-channel infrared dual-band panoramic imager was designed using spatial multicamera image mosaicking. Each optical system of the imaging channel was designed in a double imaging configuration with an F-number of 2, working bands of MWIR 3 to 5 mu m and LWIR 8 to 12 mu m, and a full field of view (FOV) of 122 deg. By adopting refractive-diffractive hybrid optical elements and introducing aspheric designs, the system was made to achieve temperature compensation from -40 degrees C to 60 degrees C by means of optical passive athermalization. Results indicate that the system attained almost 100% cold stop efficiency. At the Nyquist frequency of 18 lp/mm, the modulation-transfer-function (MTF) of the MWIR system was higher than 0.70 at the edges of the FOV, whereas the MTF of LWIR system was greater than 0.35 for the same condition, both approaching the diffraction limit. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
入藏号: WOS:000481889000026
ISSN: 0091-3286
eISSN: 1560-2303
________________________________________
第 202 条,共 344 条
标题: Random scattering of images and visibility enhancement via stochastic resonance
作者: Zhang, YB (Zhang, Yongbin); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu)
来源出版物: OPTICAL ENGINEERING 卷: 58 期: 4 文献号: 046105 DOI: 10.1117/1.OE.58.4.046105 出版年: APR 2019
摘要: We investigate numerically the random scattering of two-dimensional (2-D) images and the visibility enhancement via stochastic resonance both in intensity and momentum spaces. The multiple scattering destroys the direct transmission of photons, but some ballistic photons carrying the image information still penetrate the scattering media. The underlying ballistic image signals exhibit an instability and are enhanced at the expense of scattering noise under self-focusing nonlinearity, which is described as a stochastic resonance. It is found that the higher ratio of ballistic signals to scattering noise triggers a stronger instability. The effect of visibility enhancement in different scattering conditions is discussed, and the 2-D quasiparticle motion model is designed to analyze the nonlinear dynamic evolution. Our results provide potential guidance for noisy image detection. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE).
入藏号: WOS:000481889000031
ISSN: 0091-3286
eISSN: 1560-2303
________________________________________
第 203 条,共 344 条
标题: Long-Short-Term Features for Dynamic Scene Classification
作者: Huang, YJ (Huang, Yuanjun); Cao, XB (Cao, Xianbin); Wang, Q (Wang, Qi); Zhang, BC (Zhang, Baochang); Zhen, XT (Zhen, Xiantong); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 卷: 29 期: 4 页: 1038-1047 DOI: 10.1109/TCSVT.2018.2823360 出版年: APR 2019
摘要: Dynamic scene classification has been extensively studied in computer vision due to its widespread applications. The key to dynamic scene classification lies in jointly characterizing spatial appearance and temporal dynamics to achieve informative representation, which remains an outstanding task in the literature. In this paper, we propose a unified framework to extract spatial and temporal features for dynamic scene representation. More specifically, we deploy two variants of deep convolutional neural networks to encode spatial appearance and short-term dynamics into short-term deep features (STDF). Based on STDF, we propose using the autoregressive moving average model to extract long-term frequency features (LTFF). By combining STDF and LTFF, we establish the long-short-term feature (LSTF) representations of dynamic scenes. The LSTF characterizes both spatial and temporal patterns of dynamic scenes for comprehensive and information representation that enables more accurate classification. Extensive experiments on three-dynamic scene classification benchmarks have shown that the proposed LSTF achieves high performance and substantially surpasses the state-of-the-art methods.
入藏号: WOS:000464149700010
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Wang, Qi                  0000-0002-7028-4956
Li, Xuelong                  0000-0002-0019-4197

ISSN: 1051-8215
eISSN: 1558-2205
________________________________________
第 204 条,共 344 条
标题: Haze-removal polarimetric imaging schemes with the consideration of airlight's circular polarization effect
作者: Zhang, WF (Zhang, Wenfei); Lang, J (Lang, Jian); Ren, LY (Ren, Liyong)
来源出版物: OPTIK 卷: 182 页: 1099-1105 DOI: 10.1016/j.ijleo.2019.01.048 出版年: APR 2019
摘要: The polarimetric dehazing methods have been proven effective in enhancing the quality of images acquired in turbid media, including in hazy weather conditions. However, traditional polarimetric dehazing methods are all based on a hypothesis that the airlight only performs linear polarization property. The circular polarization effect is usually ignored although it may be an essential component of the airlight. In this paper, we report a new polarimetirc dehazing method considering the full polarization effects of the airlight (the linear and circular polarization effects of the airlight). In addition, an effective dehazing method only using the circular polarization effect of the airlight is given. Experimental results verify the effectiveness and the universality of the proposed method, and its dehazing capacity is obviously enhanced. Meanwhile, the circular polarization effect based method also can effectively achieve dehazing result only with one intensity image and one circular polarization image. This method is much easier to implement, although the dehazing results are not comparative to that of the full polarization effects based method. The proposed methods would advance the applications of the polarimetric dehazing methods in dehazing application filed.
入藏号: WOS:000474672600138
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ren, li yong         F-5518-2014         0000-0002-7547-7511
Zhang, Wenfei                  0000-0002-4408-4352

ISSN: 0030-4026
eISSN: 1618-1336
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第 205 条,共 344 条
标题: Nonlinear Optical Response of Graphene Oxide Langmuir-Blodgett Film as Saturable Absorbers
作者: Wang, J (Wang, Jiang); Wang, YG (Wang, Yonggang); Wang, TJ (Wang, Taijin); Li, GY (Li, Guangying); Lou, R (Lou, Rui); Cheng, GH (Cheng, Guanghua); Bai, J (Bai, Jing)
来源出版物: NANOMATERIALS 卷: 9 期: 4 文献号: 640 DOI: 10.3390/nano9040640 出版年: APR 2019
摘要: Two-dimensional (2D) materials as saturable absorbers (SAs) have attracted intense interest for applications in pulsed laser generation because of their distinguishing optical properties. However, the existing methods of preparing SAs were insufficient. Here, we fabricated graphene oxide (GO) SAs by Langmuir-Blodgett (LB) methods for passively Q-switched Nd:YAG laser. The GO sheets were deposited on a quartz plate using the LB method. Two different LB-GO SAs grown under the surface pressure of 22 and 38 mN/m were obtained. Compared with the drop coating method, LB-GO SA exhibited more excellent uniformity, larger nonlinear performance and higher optical transparency. By inserting LB-GO SA into the Nd:YAG laser linear cavity, the short pulse duration of 156 ns and the average output power of 1.313 W were obtained. The slope efficiency was as high as 43.7%, due to low loss of the LB-GO SA. Our results illustrated a new way for preparing the SA using the LB technique.
入藏号: WOS:000467768800156
PubMed ID: 31010186
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Jang                  0000-0002-3969-9459

ISSN: 2079-4991
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第 206 条,共 344 条
标题: Direct Amplification of High Energy Pulsed Laser in Fiber-Single Crystal Fiber with High Average Power
作者: Li, F (Li, Feng); Yang, Z (Yang, Zhi); Lv, ZG (Lv, Zhiguo); Yang, Y (Yang, Yang); Wang, YS (Wang, Yishan); Yang, XJ (Yang, Xiaojun); Zhao, W (Zhao, Wei); Li, QL (Li, Qianglong); Wei, YF (Wei, Yufeng)
来源出版物: CRYSTALS 卷: 9 期: 4 文献号: 216 DOI: 10.3390/cryst9040216 出版年: APR 2019
摘要: A laser master oscillator power amplifier (MOPA) system consisting of a fiber amplifier and a two-stage Yb:YAG single crystal fiber (SCF) is experimentally studied. The nonlinear stimulated Raman scattering (SRS) is avoided by limiting the output power of the fiber preamplifier to 600 mW. Due to the benefit from the low nonlinearity and high amplification gain of the SCF, a laser pulse duration of 16.95 ps and a high average power of 41.7 W at a repetition rate of 250 kHz are obtained by using a two-stage polarization controlled double-pass amplification of Yb:YAG SCF, corresponding to an output energy of 166.8 J and a peak power of 9.84 MW, respectively. The polarization controlled SCF amplification scheme achieved a gain as high as more than 69 times. During the amplification, the spectra gain narrowing effect and the polarization controlled four-pass amplification setup are also studied. The laser spectrum is narrowed from over 10 nm to less than 3 nm, and the pulse width is also compressed to hundreds of femtosecond by dechirping the laser pulse. This compact-sized, cost-effective laser source can be used in laser micromachining, or as the seeder source for generating much higher power and energy laser for scientific research. For some applications which need femtosecond laser, this laser source can also be compressed to femtosecond regime.
入藏号: WOS:000467300100036
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
qianglong, li         V-6278-2019         
Feng, Li                  0000-0003-0846-7273

ISSN: 2073-4352
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第 207 条,共 344 条
标题: Influence of Zirconium Salt Materials on the Structure and Properties of LiZr2(PO4)(3) Lithium Ion Solid Electrolyte
作者: Li, WL (Li Wenlong); Liu, H (Liu Huan); Yuan, K (Yuan Kang); Yang, LQ (Yang Liqing); Zhou, QQ (Zhou Qianqian); Wang, HJ (Wang Haojing); Zhang, H (Zhang Hong)
来源出版物: RARE METAL MATERIALS AND ENGINEERING 卷: 48 期: 4 页: 1298-1303 出版年: APR 2019
摘要: Samples of LiZr2(PO4)(3) compound with pure phase, adopting the method of solid phase and liquid phase method, were obtained by pressureless sintering from different zirconium salt raw materials. And LiZr2(PO4)(3) Li-ion solid electrolytes were characterized through X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical impedance (EIS). Analyzing the results of the test, the influence of different zirconium salt raw materials on the structure and performance of LiZr2(PO4)(3) solid electrolytes was studied. The results show that the room-temperature stable alpha-LiZr2(PO4)(3) (rhombohedral phase) was prepared from zirconium acetate. While synthetic LiZr2(PO4)(3) prepared from the other three kinds of zirconium salt raw materials exists in triclinic phase. Rhombohedral phase LiZr2(PO4)(3) lithium ion solid state electrolyte sample prepared from different zirconium raw materials shows the highest total conductivity of 2.25x10(-5) S/cm, and the lowest activation energy of 0.28 eV.
入藏号: WOS:000467321400042
ISSN: 1002-185X
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第 208 条,共 344 条
标题: A Sparse Constrained Graph Regularized Nonnegative Matrix Factorization Algorithm for Hyperspectral Unmixing
作者: Gan, YQ (Gan Yu-quan); Liu, WH (Liu Wei-hua); Feng, XP (Feng Xiang-peng); Yu, T (Yu Tao); Hu, BH (Hu Bing-hang); Wen, DS (Wen De-sheng)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS 卷: 39 期: 4 页: 1118-1127 DOI: 10.3964/j.issn.1000-0593(2019)04-1118-10 出版年: APR 2019
摘要: The space resolution of hyperspectral image is influenced due to the restriction of sensor platform, which results in more than one material in one pixel. Such kind of pixel is called mixed pixel. The existence of mixed pixels restricts accurate analysis and application of hyperspectral images. Hyperspectral unmixing technique can factorize mixed pixels to pure material signatures (endmembers) and corresponding proportion (abundance), which makes more accurate material signature available. Unmxing is very important to accurate classification and identification, anomaly detection and quantitative analysis for hyperspectral imagery. Based on linear spectral mixing model, this paper develops an endmember and abundance sparse constrained graph regularized nonnegative matrix factorization (EAGLNMF) algorithm for hyperspectral imagery unmixing. The algorithm is based on nonnegative matrix factorization, and integrates graph regularization and both endmember and abundance sparse constraints to the object function. Graph regularization is used to consider the geometrical structure of the hyperspectral image and sparse constraints can demonstrate the inner manifoldstructure. First, the lost function of EAGLNMF is constructed, and VCA-FCLS method is used as initial value. And then, the value of the parameters is set, including weighting matrix of graph regularization, sparse factors for both endmember signature matrix and abundance matrix. At last, the iteration equations for endmember matrix and abundance matrix are both obtained, and stopping criteria is given. The algorithm does not require pure pixel in the hyperspectral image. In fact, there are little pure pixel in real hyperspectral imagerydue to the sensors platform. Thus, EAGLNMF algorithm provides a kind of solution for real hyperspectral imagery. The availability and effect of EAGLNMF are verified by synthetic data via four experiments. The experiments compare EAGLNMF with VCA-FCLS, standard NMF and GLNMF. Two metrics, spectral angle distance (SAD) and abundance angle distance (AAD) are used to compare the four methods. Experiment 1 is total comparison experiment of the four methods. SNR and the number of endmembers are constant, and the value of SAD and AAD are compared. Experiment 2 evaluates the influence of SNR. Different value for SNR and constant value for number of endmembers are given to different runs. Experiment 3 evaluates the influence of number of endmembers. Different value for number of endmembers and constant value for SNR are given to different runs. The experiment result shows that EAGLNMF method obtains more accurate result for both endmebers and abundance. Moreover, experiment 4 evaluates the influence of sparse factor between endmember signature and abundance. The result demonstrates that endmember sparse constraint shows a positive effect to unmixing. And, sparse factor between endmember signature and abundance shows effect to unmixing result. In addition, real AVIRIS hyperspectral image is applied to VCA-FCLS, standard NMF, GLNMF and the proposed EAGLNMF, and compared with the ground truth of USGS, the result shows that EAGLNMF obtains best unmixing result among the four algorithms and the accuracy of the estimated endmembers is good.
入藏号: WOS:000466450300022
ISSN: 1000-0593
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第 209 条,共 344 条
标题: A chiral long-period grating fabrication method based on axis-offset rotating optical fiber
作者: Kong, XD (Kong, Xudong); Ren, LY (Ren, Liyong); Liang, J (Liang, Jian); Ren, KL (Ren, Kaili); Ju, HJ (Ju, Haijuan); Xu, YP (Xu, Yiping); Xu, CF (Xu, Chengfang)
来源出版物: OPTICAL AND QUANTUM ELECTRONICS 卷: 51 期: 4 文献号: 124 DOI: 10.1007/s11082-019-1841-9 出版年: APR 2019
摘要: We propose a method to fabricate chiral long-period grating (CLPG) by rotating the standard single mode fiber which is fixed on two fiber holders but with an axis-offset. We show that, compared with traditional fabrication methods, this axis-offset method is capable of obtaining identical resonance wavelengths of the CLPGs for the same grating period. We investigate the performance of CLPGs by detecting the interference between the light emerging from CLPGs and a reference light. The achieved forklike and spiral interference patterns both confirm the generation of +/- 1-order optical vortex through CLPG. Experimental results indicate that high-quality CLPGs can be easily and repeatedly fabricated by this method.
入藏号: WOS:000463997700002
ISSN: 0306-8919
eISSN: 1572-817X
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第 210 条,共 344 条
标题: Thermal Stability Analysis and Experimental Study of a New Type of Grid-Reinforced Carbon Fiber Mirror
作者: Xu, L (Xu, Liang); Ding, JT (Ding, Jiaoteng); Wang, YJ (Wang, Yongjie); Xie, YJ (Xie, Yongjie); Wu, XG (Wu, Xiaoge); Ma, Z (Ma, Zhen)
来源出版物: APPLIED COMPOSITE MATERIALS 卷: 26 期: 2 页: 469-478 DOI: 10.1007/s10443-018-9705-1 出版年: APR 2019
摘要: Due to low density, high specific stiffness, and low thermal expansion, carbon fiber reinforced plastic (CFRP) is one of potential materials for high precise components. For high precise structures such as reflectors and optical mirrors, usually strict thermal stability required. In order to ensure rigidity and thermal deformation resistance, carbon fiber mirrors are usually designed as a grid-reinforced sandwich structure. In order to improve the thermal stability of carbon fiber mirrors, a new type of grid-reinforced sandwich structure design is proposed. Finite element method was used to analyze the thermal deformations of the carbon fiber mirror without manufacturing error and with manufacturing error. In order to overcome the effect of moisture absorption deformation, thermal deformation test of the carbon fiber mirror was performed in a vacuum tank. The test results verify the reliability of the finite element analysis results. For phi 100mm center aperture of the phi 150mm carbon fiber mirror, the test results show that the thermal stability is about 4nm/degrees C, which is enough for optical mirror application, although grid effect existed.
入藏号: WOS:000463170900003
ISSN: 0929-189X
eISSN: 1573-4897
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第 211 条,共 344 条
标题: Histograms of Gaussian normal distribution for 3D feature matching in cluttered scenes
作者: Zhou, W (Zhou, Wei); Ma, CW (Ma, Caiwen); Yao, T (Yao, Tong); Chang, P (Chang, Peng); Zhang, Q (Zhang, Qi); Kuijper, A (Kuijper, Arjan)
来源出版物: VISUAL COMPUTER 卷: 35 期: 4 页: 489-505 DOI: 10.1007/s00371-018-1478-x 出版年: APR 2019
摘要: 3D feature descriptors provide essential information to find given models in captured scenes. In practical applications, these scenes often contain clutter. This imposes severe challenges on the 3D object recognition leading to feature mismatches between scenes and models. As such errors are not fully addressed by the existing methods, 3D feature matching still remains a largely unsolved problem. We therefore propose our Histograms of Gaussian Normal Distribution (HGND) for capturing salient feature information on a local reference frame (LRF) that enables us to solve this problem. We define a LRF on each local surface patch by using the eigenvectors of the scatter matrix. Different from the traditional local LRF-based methods, our HGND descriptor is based on the combination of geometrical and spatial information without calculating the distribution of every point and its geometrical information in a local domain. This makes it both simple and efficient. We encode the HGND descriptors in a histogram by the geometrical projected distribution of the normal vectors. These vectors are based on the spatial distribution of the points. We use three public benchmarks, the Bologna, the UWA and the Ca' Foscari Venezia dataset, to evaluate the speed, robustness, and descriptiveness of our approach. Our experiments demonstrate that the HGND is fast and obtains a more reliable matching rate than state-of-the-art approaches in cluttered situations.
入藏号: WOS:000463672800003
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhou, Wei                  0000-0001-8328-3736

ISSN: 0178-2789
eISSN: 1432-2315
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第 212 条,共 344 条
标题: A star identification algorithm based on radial and dynamic cyclic features of star pattern
作者: Wei, X (Wei, Xin); Wen, DS (Wen, Desheng); Song, ZX (Song, Zongxi); Xi, JB (Xi, Jiangbo); Zhang, WK (Zhang, Weikang); Liu, G (Liu, Gang); Li, ZX (Li, Zhixin)
来源出版物: ADVANCES IN SPACE RESEARCH 卷: 63 期: 7 页: 2245-2259 DOI: 10.1016/j.asr.2018.12.027 出版年: APR 1 2019
摘要: A full-sky star identification algorithm based on radial and dynamic cyclic patterns is presented with the aim of solving the "lost-in-space" problem. The dynamic cyclic pattern match is applied with a maximum cumulate comparison method to identify sensor-catalog pairings in initial match, which substantially eliminates the effects of the star position noise, magnitude noise, and false stars. After initial match pairings of stars are obtained, a chain part extension technique is employed to quickly search for the longest match chain as the final result. Experimental results indicate that the proposed algorithm is highly robust to star position noise, magnitude noise and false stars. In a series of simulations, the identification rate of the algorithm is 97.50% with 2.0 pixels star position noise, 96.90% with 0.4 Mv star magnitude noise and 95.30% with four false stars respectively. Moreover, the algorithm achieves an identification rate of 58.08% when only six stars are in the field of view. (C) 2018 COSPAR. Published by Elsevier Ltd. All rights reserved.
入藏号: WOS:000463131800023
ISSN: 0273-1177
eISSN: 1879-1948
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第 213 条,共 344 条
标题: Fast design method of smooth freeform lens with an arbitrary aperture for collimated beam shaping
作者: Mao, XL (Mao, Xianglong); Li, JP (Li, Jinpeng); Wang, FB (Wang, Fengbiao); Gao, R (Gao, Rong); Li, X (Li, Xing); Xie, YJ (Xie, Yongjun)
来源出版物: APPLIED OPTICS 卷: 58 期: 10 页: 2512-2521 DOI: 10.1364/AO.58.002512 出版年: APR 1 2019
摘要: A method is presented for the fast design of a smooth freeform lens to tailor a collimated light beam with an arbitrary contour. This method begins by calculating an initial surface based on a simplified ray mapping. Then the surface is fitted by a system of Zernike polynomials, whose weights are treated as the optimization variables for further optimization. In the optimization, the objective function is analytically calculated using a partial differential-equation-based approach. To validate the effectiveness of the proposed method, a freeform lens is designed for a collimated Gaussian beam with a spline contour to form a uniform illumination distribution with another spline contour, which takes only 26 s. A freeform lens is also fabricated and experimented, and its practical performance approaches the design. (C) 2019 Optical Society of America
入藏号: WOS:000462833000028
PubMed ID: 31045046
ISSN: 1559-128X
eISSN: 2155-3165
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第 214 条,共 344 条
标题: Deep Binary Reconstruction for Cross-Modal Hashing
作者: Hu, D (Hu, Di); Nie, FP (Nie, Feiping); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON MULTIMEDIA 卷: 21 期: 4 页: 973-985 DOI: 10.1109/TMM.2018.2866771 出版年: APR 2019
摘要: To satisfy the huge storage space and organization capacity requirements in addressing big multimodal data, hashing techniques have been widely employed to learn binary representations in cross-modal retrieval tasks. However, optimizing the hashing objective under the necessary binary constraint is truly a difficult problem. A common strategy is to relax the constraint and perform individual binarizations over the learned real-valued representations. In this paper, in contrast to conventional two-stage methods, we propose to directly learn the binary codes, where the model can be easily optimized by a standard gradient descent optimizer. However, before that, we present a theoretical guarantee of the effectiveness of the multimodal network in preserving the inter-and intra-modal consistencies. Based on this guarantee, a novel multimodal deep binary reconstruction model is proposed, which can be trained to simultaneously model the correlation across modalities and learn the binary hashing codes. To generate binary codes and to avoid the tiny gradient problem, a novel activation function first scales the input activations to suitable scopes and, then, feeds them to the tanh function to build the hashing layer. Such a composite function is named adaptive tanh. Both linear and nonlinear scaling methods are proposed and shown to generate efficient codes after training the network. Extensive ablation studies and comparison experiments are conducted for the image2text and text2image retrieval tasks; the method is found to outperform several state-of-the-art deep-learning methods with respect to different evaluation metrics.
入藏号: WOS:000462413700013
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Nie, Feiping         B-3039-2012         
Li, Xuelong         Z-3785-2019         
Nie, Feiping                  0000-0002-0871-6519
Li, Xuelong                  0000-0002-0019-4197

ISSN: 1520-9210
eISSN: 1941-0077
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第 215 条,共 344 条
标题: Lunar farside to be explored by Chang'e-4
作者: Wu, WR (Wu, Weiren); Li, CL (Li, Chunlai); Zuo, W (Zuo, Wei); Zhang, HB (Zhang, Hongbo); Liu, JJ (Liu, Jianjun); Wen, WB (Wen, Weibin); Su, Y (Su, Yan); Ren, X (Ren, Xin); Yan, J (Yan, Jun); Yu, DY (Yu, Dengyun); Dong, GL (Dong, Guangliang); Wang, C (Wang, Chi); Sun, ZZ (Sun, Zezhou); Liu, EH (Liu, Enhai); Yang, JF (Yang, Jianfeng); Ouyang, ZY (Ouyang, Ziyuan)
来源出版物: NATURE GEOSCIENCE 卷: 12 期: 4 页: 222-223 DOI: 10.1038/s41561-019-0341-7 出版年: APR 2019
入藏号: WOS:000462621700002
ISSN: 1752-0894
eISSN: 1752-0908
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第 216 条,共 344 条
标题: Flexible Affinity Matrix Learning for Unsupervised and Semisupervised Classification
作者: Fang, XZ (Fang, Xiaozhao); Han, N (Han, Na); Wong, WK (Wong, Wai Keung); Teng, SH (Teng, Shaohua); Wu, JG (Wu, Jigang); Xie, SL (Xie, Shengli); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 卷: 30 期: 4 页: 1133-1149 DOI: 10.1109/TNNLS.2018.2861839 出版年: APR 2019
摘要: In this paper, we propose a unified model called flexible affinity matrix learning (FAML) for unsupervised and semisupervised classification by exploiting both the relationship among data and the clustering structure simultaneously. To capture the relationship among data, we exploit the self-expressiveness property of data to learn a structured matrix in which the structures are induced by different norms. A rank constraint is imposed on the Laplacian matrix of the desired affinity matrix, so that the connected components of data are exactly equal to the cluster number. Thus, the clustering structure is explicit in the learned affinity matrix. By making the estimated affinity matrix approximate the structured matrix during the learning procedure, FAML allows the affinity matrix itself to be adaptively adjusted such that the learned affinity matrix can well capture both the relationship among data and the clustering structure. Thus, FAML has the potential to perform better than other related methods. We derive optimization algorithms to solve the corresponding problems. Extensive unsupervised and semisupervised classification experiments on both synthetic data and real-world benchmark data sets show that the proposed FAML consistently outperforms the state-of-the-art methods.
入藏号: WOS:000461854100013
PubMed ID: 30137017
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Han, Na                  0000-0002-9639-7633
Li, Xuelong                  0000-0002-0019-4197
Wong, Wai Keung                  0000-0002-5214-7114
TENG, Shaohua                  0000-0002-7204-1288

ISSN: 2162-237X
eISSN: 2162-2388
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第 217 条,共 344 条
标题: Influence of two-photon absorption and free-carrier effects on all-optical logic gates in silicon waveguides
作者: Wu, W (Wu, Wei); Sun, QB (Sun, Qibing); Wang, LR (Wang, Leiran); Wang, GX (Wang, Guoxi); Zeng, C (Zeng, Chao); Zhang, ZD (Zhang, Zhaodong); Zhang, LX (Zhang, Lingxuan); Zhang, QH (Zhang, Qihao); Zheng, AH (Zheng, Aihu); Cheng, D (Cheng, Dong); Zhao, W (Zhao, Wei); Zhang, WF (Zhang, Wenfu)
来源出版物: APPLIED PHYSICS EXPRESS 卷: 12 期: 4 文献号: 042005 DOI: 10.7567/1882-0786/ab066f 出版年: APR 1 2019
摘要: We investigate the impact of two-photon absorption (TPA) and free-carrier effects on all-optical logic gates in silicon waveguides, in which the conversion efficiency is greatly reduced and the waveform is seriously distorted. A silicon-organic hybrid dual-slot waveguide without TPA is proposed for all-optical logic gates and could offer an extremely large nonlinear parameter higher than 1.4 x 10(7) W-1 km(-1). The all-optical logic AND, OR, and XOR gates based on four-wave mixing in this waveguide are realized for 100 Gb s(-1) data signals in the C-band. These results provide potential applications for all-optical signal processing in integrated optics, optical communications, and optical computation. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000461827700002
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zeng, Chao                  0000-0003-0097-6399

ISSN: 1882-0778
eISSN: 1882-0786
________________________________________
第 218 条,共 344 条
标题: A scanning-free wide-field single-fiber endoscopic image retrieval method based on optical transmission matrix
作者: Xu, CF (Xu, Chengfang); Zhuang, B (Zhuang, Bin); Geng, Y (Geng, Yi); Chen, H (Chen, Hui); Ren, LY (Ren, Liyong); Wu, ZX (Wu, Zhaoxin)
来源出版物: LASER PHYSICS 卷: 29 期: 4 文献号: 046202 DOI: 10.1088/1555-6611/ab0365 出版年: APR 2019
摘要: Light waves transmitting in a multimode optical fiber (MMF) for endoscopic imaging, due to modal dispersion, inevitably suffer two severe distortions: on the way in for illuminating and on the way out for imaging, which becomes a big challenge when using a single MMF for endoscopic applications. In this paper, based on obtaining the optical transmission matrix of the MMF working in the endoscopic mode, we propose a new method for retrieving endoscopic images from speckle fields, where the two distortions could be eliminated simultaneously. Our experimental results demonstrate that the object images can be well reconstructed directly from distorted waves. In addition, no scanning operation is required when collecting images, which is timesaving. Such an efficient method might have potential applications for wide-field and ultrathin fiber endoscopic imaging.
入藏号: WOS:000460533800001
ISSN: 1054-660X
eISSN: 1555-6611
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第 219 条,共 344 条
标题: 2 mu m vector mode-locked pulses from Tm:Y2O3 ceramics laser
作者: Zhou, W (Zhou, Wei); Huang, HT (Huang, Haitao); Chen, X (Chen, Xiang); Wang, JR (Wang, Jingru); Xu, R (Xu, Rui); Wang, HT (Wang, Haotian); Zhao, YG (Zhao, Yongguang); Tang, DY (Tang, Dingyuan); Wang, YS (Wang, Yishan); Shen, DY (Shen, Deyuan)
来源出版物: LASER PHYSICS 卷: 29 期: 4 文献号: 045301 DOI: 10.1088/1555-6611/aaffc4 出版年: APR 2019
摘要: We report on stable passively mode-locked (ML) pulses with Tm:Y2O3 ceramics operating at a 2 mu m wavelength range for the first time. With a SESAM, synchronous ML pulses with dual-wavelengths are obtained, with a typical pulse width of 40 ps, a maximum output average power of 240 mW and a pulse repetition rate of similar to 124 MHz. The output pulses were further proved to be stable polarization-locked vector pulses. To our knowledge, this is also the first observation of vector pulses in 2 mu m ML solid-state oscillators.
入藏号: WOS:000459991700001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhao, Yongguang         AAA-8963-2019         

ISSN: 1054-660X
eISSN: 1555-6611
________________________________________
第 220 条,共 344 条
标题: Auxiliary structure of nano-pinnacle prepared on silicon substrate: Improving the emission intensity by 9 times in SSI-LEDs
作者: Liu, LG (Liu, Lingguang); Wang, YG (Wang, Yaogong); Lin, YY (Lin, Yuanyuan); Zhang, XN (Zhang, Xiaoning); Kuo, Y (Kuo, Yue); Tian, JS (Tian, Jinshou)
来源出版物: MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING 卷: 93 页: 226-230 DOI: 10.1016/j.mssp.2019.01.010 出版年: APR 2019
摘要: Auxiliary structure of nano-pinnacle is prepared on silicon substrate of SSI-LEDs device, and the micro-structure properties, electrical and optical characteristics of the proposed structure device are investigated. Non-uniform size and geometry of nano-pinnacles are prepared by wet-etching, and the most frequent geometry is similar to 230 x 140 nm pyramids. With help of the nano-pinnacle structure, the electric field strength distributed on treated surface of the nano-pinnacle sample is enhanced by similar to 4 times, resulting in the increase of the density of conducive paths by 3.6 times. By exploring the electrical and optical results, the onset voltage of light emission is decreased by 60% from - 7.6 V to - 3.4 V, and the emission intensity and efficiency are improved by similar to 9 times and similar to 8 times, respectively compared with the traditional structure device of SSI-LEDs.
入藏号: WOS:000457727300027
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Kuo, Yue                  0000-0003-2757-1842

ISSN: 1369-8001
eISSN: 1873-4081
________________________________________
第 221 条,共 344 条
标题: Query-aware sparse coding for web multi-video summarization
作者: Ji, Z (Ji, Zhong); Ma, YR (Ma, Yaru); Pang, YW (Pang, Yanwei); Li, XL (Li, Xuelong)
来源出版物: INFORMATION SCIENCES 卷: 478 页: 152-166 DOI: 10.1016/j.ins.2018.09.050 出版年: APR 2019
摘要: Given the explosive growth of online videos, it is becoming increasingly important to relieve the tedious work of browsing and managing the video content of interest. Video summarization aims at providing such a technique by transforming one or multiple videos into a compact one. However, conventional multi-video summarization methods often fail to produce satisfying results as they ignore the users' search intents. To this end, this paper proposes a novel query-aware approach by formulating the multi-video summarization in a sparse coding framework, where the web images searched by a query are taken as the important preference information to reveal the query intent. To provide a user-friendly summarization, this paper also develops an event-keyframe presentation structure to present keyframes in groups of specific events related to the query by using an unsupervised multi-graph fusion method. Moreover, we release a new public dataset named MVS1K, which contains about 1000 videos from 10 queries and their video tags, manual annotations, and associated web images. Extensive experiments on the MVS1K and TVSum datasets demonstrate that our approaches produce competitively objective and subjective results. (C) 2018 Published by Elsevier Inc.
入藏号: WOS:000457666500010
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Ji, Zhong                  0000-0002-2197-3739

ISSN: 0020-0255
eISSN: 1872-6291
________________________________________
第 222 条,共 344 条
标题: Observation of evolution dynamics from bound states to single-pulse states in a passively mode-locked fiber laser
作者: Wang, GM (Wang, Guomei); Chen, GW (Chen, Guangwei); Li, WL (Li, Wenlei); Zeng, C (Zeng, Chao); Zhao, W (Zhao, Wei)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 9 文献号: 1950103 DOI: 10.1142/S0217984919501033 出版年: MAR 30 2019
摘要: We report what is, to our knowledge, the first experimental observation of the ultrafast evolution dynamics from bound states (BSs) to single-pulse states (SPSs) by using the dispersive Fourier-transform (DFT) technique. The evolutions from three categories of initial BSs to SPSs are spectrally resolved in real time. Usually, accompanied by complex soliton-soliton interaction and competition, one of the two bound pulses weakens to disappearance, and the other one evolves into SPS. During the transition, the two bound pulses ordinarily depart away from each other with complex changes of relative phase. However, it is found that not all the evolutions are accompanied by the increase of temporal separation between two bound pulses. The obtained results would facilitate a deep understanding of complex dynamics in nonlinear systems and provide valuable data for further theoretical studies.
入藏号: WOS:000463148900005
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 223 条,共 344 条
标题: Novel electronic readout system for micro-channel plate detector with wedge and strip anode
作者: Xu, N (Xu, Neng); Liu, YA (Liu, Yong'an); Sheng, LZ (Sheng, Lizhi); Su, T (Su, Tong); Chen, C (Chen, Chen); Li, Y (Li, Yao); Zhao, BS (Zhao, Baosheng); Liu, CL (Liu, Chunliang)
来源出版物: JOURNAL OF MODERN OPTICS 卷: 66 期: 6 页: 697-701 DOI: 10.1080/09500340.2019.1567844 出版年: MAR 30 2019
摘要: A micro-channel plate detector with wedge and strip anode can be used for visible and ultraviolet light imaging. In this paper, the imager electronics are designed in order to process specific output charge characteristics. The original signal output from the detector is shaped into a Gaussian pulse signal, and a digital Constant Fraction Discriminator is used to judge the arrival time of the pulse. The resolution of the electronic output image is 1024 x 1024, and the position decoding accuracy is 1 pixel. The experimental imaging resolving power of the detector is as high as 70 mu m.
入藏号: WOS:000459542100014
ISSN: 0950-0340
eISSN: 1362-3044
________________________________________
第 224 条,共 344 条
标题: Dimensionality reduction based on parallel factor analysis model and independent component analysis method
作者: Yan, RH (Yan, Ronghua); Peng, JY (Peng, Jinye); Ma, DM (Ma, Dongmei)
来源出版物: JOURNAL OF APPLIED REMOTE SENSING 卷: 13 期: 1 文献号: 014532 DOI: 10.1117/1.JRS.13.014532 出版年: MAR 29 2019
摘要: In hyperspectral image (HSI) analysis, dimensionality reduction is a preprocessing step for HSI classification. Independent component analysis (ICA) reduces the spectral dimension and does not utilize the spatial information of the HSI. To solve it, tensor decompositions have been successfully applied to joint noise reduction in spatial and spectral dimensions of HSIs, such as parallel factor analysis (PARAFAC). However, the PARAFAC method does not reduce the dimension in the spectral dimension. We proposed a method to improve it, which combines ICA and PARAFAC to reduce both the dimension in the spectral dimension and the noise in the spatial and spectral dimensions. The experimental results indicate that this method improves the classification compared with the previous methods. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)
入藏号: WOS:000463292300001
ISSN: 1931-3195
________________________________________
第 225 条,共 344 条
标题: Performance analysis of different pixel-wise processing methods for depth imaging with single photon detection data
作者: Kang, Y (Kang, Yan); Li, LF (Li, Lifei); Li, DJ (Li, Dongjian); Liu, DW (Liu, Dawei); Zhang, TY (Zhang, Tongyi); Zhao, W (Zhao, Wei)
来源出版物: JOURNAL OF MODERN OPTICS 卷: 66 期: 9 页: 976-985 DOI: 10.1080/09500340.2019.1596322 提前访问日期: MAR 2019 出版年: MAY 21 2019
摘要: We establish a long-range single photon counting three-dimensional (3D) imaging system based on cage optical structure. Five different pixel-wise processing methods for time-of-flight (TOF) photon counting data are compared with data collected by our 3D imaging system for ranges 40-700 m and a suitable representation model for photon counting data is proposed for pixel-wise processing. Experimental results show that these methods exploit the instrumental response function (IRF), yielding a high-quality 3D image. When the signal photon counts are greater than 13 per pixel, the resulting mean absolute error (MAE) values of the IRF-based methods are better than results from the non-IRF-based methods. Regarding IRF-based methods, the union of subspace (UOS) model-based approach and cross correlation are more suitable than the Markov chain Monte Carlo (MCMC) method in the condition of a small number of return signal photons. These results offer valuable information to promote the implementation of photon counting 3D imaging in real applications.
入藏号: WOS:000465775700001
ISSN: 0950-0340
eISSN: 1362-3044
________________________________________
第 226 条,共 344 条
标题: Muti-stage learning for gender and age prediction
作者: Fang, J (Fang, Jie); Yuan, Y (Yuan, Yuan); Lu, XQ (Lu, Xiaoqiang); Feng, YC (Feng, Yachuang)
来源出版物: NEUROCOMPUTING 卷: 334 页: 114-124 DOI: 10.1016/j.neucom.2018.12.073 出版年: MAR 21 2019
摘要: Automatic gender and age prediction has become relevant to an increasing amount of applications, particularly under the rise of social platforms and social media. However, the performances of existing methods on real-world images are still not satisfactory as we expected, especially when compared to that of face recognition. The reason is that, facial images for gender and age prediction have inherent small inter-class and big intra-class differences, i.e., two images with different skin colors and same age category label have big intra-class difference. However, most existing methods have not constructed discriminative representations for digging out these inherent characteristics very well. In this paper, a method based on muti-stage learning is proposed: The first stage is marking the object regions with an encoder-decoder based segmentation network. Specifically, the segmentation network can classify each pixel into two classes, "people" and others, and only the "people" regions are used for the subsequent processing. The second stage is precisely predicting the gender and age information with the proposed prediction network, which encodes global information, local region information and the interactions among different local regions into the final representation, and then finalizes the prediction. Additionally, we evaluate our method on three public and challenging datasets, and the experimental results verify the effectiveness of our proposed method. (C) 2019 Elsevier B.V. All rights reserved.
入藏号: WOS:000458626300011
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0925-2312
eISSN: 1872-8286
________________________________________
第 227 条,共 344 条
标题: Optical vortex shaping via a phase jump factor
作者: Ma, HX (Ma, Haixiang); Li, XZ (Li, Xinzhong); Zhang, H (Zhang, Hao); Tang, J (Tang, Jie); Li, HH (Li, Hehe); Tang, MM (Tang, Miaomiao); Wang, JG (Wang, Jingge); Cai, YJ (Cai, Yangjian)
来源出版物: OPTICS LETTERS 卷: 44 期: 6 页: 1379-1382 DOI: 10.1364/OL.44.001379 出版年: MAR 15 2019
摘要: Topological charge (TC) of an optical vortex (OV) is a crucial parameter. We propose two factors, namely, the phase jump factor and the phase gradient factor, to replace the parameter of TC through unwrapping the TC definition integral. Based on these two factors, we report on a novel OV, referred to as the remainder-phase optical vortex (ROV). The properties of the ROV are studied in depth by adjusting these two factors. Results show that the phase gradient factor determines the total orbital angular momentum (OAM), whereas the phase jump factor decides the number of split unit vortices and reshapes the structure of the OAM distribution. This work provides a novel OV with controllable OAM distribution, which will open up new applications such as particle manipulation, beam shaping, and micro-fabrication. (C) 2019 Optical Society of America
入藏号: WOS:000461327800023
PubMed ID: 30874655
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xinzhong         P-7966-2018         0000-0002-6426-4043
Li, Hehe                  0000-0003-2347-1393
Ma, Haixiang                  0000-0001-9422-9372

ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 228 条,共 344 条
标题: Generation of a double-ring perfect optical vortex by the Fourier transform of azimuthally polarized Bessel beams
作者: Liang, YS (Liang, Yansheng); Yan, SH (Yan, Shaohui); He, MR (He, Minru); Li, MM (Li, Manman); Cai, YN (Cai, Yanan); Wang, ZJ (Wang, Zhaojun); Lei, M (Lei, Ming); Yao, BL (Yao, Baoli)
来源出版物: OPTICS LETTERS 卷: 44 期: 6 页: 1504-1507 DOI: 10.1364/OL.44.001504 出版年: MAR 15 2019
摘要: The perfect optical vortex (POV), the ring size being independent of its topological charge, has found potential applications in optical tweezers and optical communications. In this Letter, we report a new kind of POV, termed as double-ring POV (DR-POV), whose diameters of the two rings are independent of topological charge. We theoretically demonstrate that such a vortex is the Fourier transform of an azimuthally polarized Bessel beam. Experimental results agree well with theoretical prediction. We further investigate the vortex nature of the DR-POV through an interferometric method, showing that the two rings of the vortex have the same topological charge value (magnitude and sign). The specular properties of the DR-POV may find application in optical tweezers, such as trapping and rotating of low-refractive-index particles in the dark region between the two rings. (C) 2019 Optical Society of America
入藏号: WOS:000461327800055
PubMed ID: 30874687
ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 229 条,共 344 条
标题: 1.8-2.7 mu m emission from As-S-Se chalcogenide glasses containing ZnSe: Cr2+ particles
作者: Yang, AP (Yang, Anping); Qiu, JH (Qiu, Jiahua); Ren, J (Ren, Jing); Wang, RP (Wang, Rongping); Guo, HT (Guo, Haitao); Wang, YW (Wang, Yuwei); Ren, H (Ren, He); Zhang, J (Zhang, Jian); Yang, ZY (Yang, Zhiyong)
来源出版物: JOURNAL OF NON-CRYSTALLINE SOLIDS 卷: 508 页: 21-25 DOI: 10.1016/j.jnoncrysol.2019.01.007 出版年: MAR 15 2019
摘要: Mid-infrared (MIR) light sources are indispensable in modern photonic society. In this work, the composites of the As-S-Se chalcogenide glasses containing MIR-emitting ZnSe: Cr2+ submicron-particles are fabricated by two methods, melt-quenching and hot-pressing. The MIR refractive index, transmittance and photoluminescence properties are investigated and compared in the composites prepared by the two methods. Benefiting from the wide glass forming region of the As-S-Se system, it is possible, by tuning the glass composition, to find a glass (e.g., As40S57Se3) with the refractive index well matching that of the ZnSe: Cr2+ crystal. The composites prepared by the melt-quenching method have higher MIR transmittance, but the MIR emission can only be observed in the samples prepared by the hot-pressing technique. The corresponding reasons are discussed based on microstructural analyses. The results reported in this article could provide helpful theoretical and experimental information for making novel broadband MIR-emitting sources based on chalcogenide glasses.
入藏号: WOS:000459357800004
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Rongping         N-2867-2019         0000-0002-4426-824X
Yang, Zhiyong         H-1309-2013         0000-0003-1070-2498

ISSN: 0022-3093
eISSN: 1873-4812
________________________________________
第 230 条,共 344 条
标题: Probability Analysis and Control of River Runoff-sediment Characteristics based on Pair-Copula Functions: The Case of the Weihe River and Jinghe River
作者: You, QY (You, Qiying); Jiang, H (Jiang, Hao); Liu, Y (Liu, Yan); Liu, Z (Liu, Zhao); Guan, ZL (Guan, Zilong)
来源出版物: WATER 卷: 11 期: 3 文献号: 510 DOI: 10.3390/w11030510 出版年: MAR 12 2019
摘要: Analyzing the encounter frequency of high-low runoff and sediment yield is important for the appropriate dispatching of runoff-sediment resources, as well as river regulation. However, there have been no reports on the utilization of the pair-copula function in analyzing the runoff-sediment characteristics from a probabilistic perspective and conducting probability control on the runoff-sediment yields of different hydrologic stations. This paper builds marginal distribution functions on the basis of kernel distribution theory. In addition, this paper builds the joint distribution functions through pair-copula functions in order to analyze the encounter probability and the compensation characteristics of high-low runoff and sediment at different stations on the Weihe River in China, as well as the origins of runoff-sediment, to conduct probability control of river runoff-sediment resource allocation. The results show that, in different periods, the synchronous probability of high-low runoff of the Weihe River's Xianyang and Huaxian Stations, and the Jinghe River's Zhangjiashan Station differ, while that of high-low sediment at the three stations changes little-remaining at around 54%. Therefore, the sediment and runoff of the Weihe River apparently have different origins. In years of high and low runoff, if the runoffs of the Xianyang and Zhangjiashan Stations can be kept within a certain range, then the runoff of the Huaxian Station will be in a particular range, at a certain probability. Sediment at the Huaxian Station can be controlled, in a similar way. These results are of great significance for the water and sediment management department of the Weihe river, in order to reasonably allocate water and sediment resources.
入藏号: WOS:000464527500009
ISSN: 2073-4441
________________________________________
第 231 条,共 344 条
标题: Optical sorting of small chiral particles by tightly focused vector beams
作者: Li, MM (Li, Manman); Yan, SH (Yan, Shaohui); Zhang, YA (Zhang, Yanan); Liang, YS (Liang, Yansheng); Zhang, P (Zhang, Peng); Yao, BL (Yao, Baoli)
来源出版物: PHYSICAL REVIEW A 卷: 99 期: 3 文献号: 033825 DOI: 10.1103/PhysRevA.99.033825 出版年: MAR 12 2019
摘要: The identification and separation of substances by chirality has always been an important problem in biomedical research and industry. Light beams carry optical momentum, and can exert optical force on any object they impinge due to the transfer of momentum. Different chiral objects will experience different optical forces when illuminated by the same light beam. We demonstrate here, based on the dipolar approximation, that a tightly focused vector beam can selectively trap and rotate small chiral particles in the transverse plane via the chirality-tailored optical forces. The radial optical force can transversely trap the chiral particles off axis or push them away depending on the real part of the chirality parameter, while the lateral optical force manifesting as the azimuthal optical force can drive the trapped particles to orbitally rotate with opposite chiral absorption in opposite directions. The study reported here may find applications in discriminating and separating chiral objects with specified chirality.
入藏号: WOS:000461050600010
ISSN: 2469-9926
eISSN: 2469-9934
________________________________________
第 232 条,共 344 条
标题: Polarization de-multiplexing using a modified Kalman filter in CO-OFDM transmissions
作者: Jiang, Y (Jiang, Yang); Yi, XW (Yi, Xingwen); Hu, SH (Hu, Shaohua); Huang, XT (Huang, Xiatao); Tang, W (Tang, Wei); Zhou, WJ (Zhou, Wenjing); Huang, XN (Huang, Xinning); Zhang, J (Zhang, Jing); Qiu, K (Qiu, Kun)
来源出版物: CHINESE OPTICS LETTERS 卷: 17 期: 3 文献号: 030603 DOI: 10.3788/COL201917.030603 出版年: MAR 10 2019
摘要: We propose the modified Kalman filter (MKF) using the received signal for observation and constructing an inverse process of the conventional Kalman filter (CKF) for polarization de-multiplexing in coherent optical (CO) orthogonal frequency-division multiplexing (OFDM) transmissions. The MKF can avoid the convergence error problem in CKF without matrix inverse operation and has a faster converging speed and a much larger tolerance to the process and measurement noise covariance, about two orders of magnitude more than those of CKF. We experimentally demonstrate the 12 Gbaud OFDM signal transmission over 480 km standard single-mode fiber. The performance of MKF and CKF outperforms pilot-aided polarization de-multiplexing with better accuracy and nonlinearity tolerance.
入藏号: WOS:000462481100005
ISSN: 1671-7694
________________________________________
第 233 条,共 344 条
标题: Thermal hydraulic performance of a microchannel heat sink for cooling a high-power diode laser bar
作者: Wu, DH (Wu, Di-Hai); Zah, CE (Zah, Chung-En); Liu, XS (Liu, Xingsheng)
来源出版物: APPLIED OPTICS 卷: 58 期: 8 页: 1966-1977 DOI: 10.1364/AO.58.001966 出版年: MAR 10 2019
摘要: Numerical and analytical methods are employed to investigate the thermal and fluid flow performance of a microchannel heat sink for cooling a high-power diode laser bar. Heat transfer characteristics and pressure drop in the microchannel under different flow rates are studied. A thermal resistance network, which is proved to have less than 5.4% error, is proposed to characterize the resistance components for the microchannel heat sink. Both numerical modeling and thermal resistance network analysis are verified by experimental results based on the wavelength shift method. Two new heat sinks with more uniform temperature distribution for laser emitters compared with the existing design are presented, and their performance is validated by numerical modeling and spatially resolved spectrum measurements. (C) 2019 Optical Society of America
入藏号: WOS:000460622500014
PubMed ID: 30874063
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ZAH, CHUNG-EN         R-3016-2019         
Wu, Di-Hai         U-9829-2018         0000-0001-8138-4242

ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 234 条,共 344 条
标题: Reconstruction of noisy images via stochastic resonance in nematic liquid crystals
作者: Feng, XP (Feng, Xingpan); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu); Zhang, YB (Zhang, Yongbin)
来源出版物: SCIENTIFIC REPORTS 卷: 9 文献号: 3976 DOI: 10.1038/s41598-019-40676-6 出版年: MAR 8 2019
摘要: We employ nematic liquid crystals as the nonlinear medium to recover noisy images via stochastic resonance, in which nonlinear coupling allows signals to grow at the expense of noise. The process is theoretically analyzed and the cross-correlation is numerically calculated. It is found that the quality of output images is affected by the input noise intensity, the applied voltage and the correlation length of noise light. Noise-hidden images can be effectively recovered by optimizing these parameters. The results suggest that nematic liquid crystals can be used for reconstruction of noisy images via stochastic resonance based on modulation instability with molecule reorientation nonlinearity.
入藏号: WOS:000460627700064
PubMed ID: 30850690
ISSN: 2045-2322
________________________________________
第 235 条,共 344 条
标题: Compound denoising method of laser speckle noise in laser inherent field imaging
作者: Cheng, ZY (Cheng Zhi-Yuan); Li, ZG (Li Zhi-Guo); She, WJ (She Wen-Ji); Xia, AL (Xia Ai-Li)
来源出版物: ACTA PHYSICA SINICA 卷: 68 期: 5 文献号: 054206 DOI: 10.7498/aps.68.20181578 出版年: MAR 5 2019
摘要: Noise is an important factor affecting the image quality of laser coherent field high resolution imaging system. And there exists not only background light additive noise but also laser multiplicative speckle noise in a laser coherent field imaging system. Both of the above noise affect the imaging quality of laser coherent field system. In order to improve the imaging quality from the perspective of noise suppression and settle the imaging quality degradation problem of laser multiplicative speckle noise and background additive noise in the laser coherent field imaging system, the model for the influence of multiplicative speckle noise and background additive noise on laser echo field demodulated signal is established in atmospheric downlink. Then, based on the model, a novel homomorphic filter and sparse matrix trace cascade compound de-noising algorithm is put forward. Firstly, based on the homomorphic filtering theory, the laser multiplicative speckle noise in the laser echo demodulated signal is converted into the additive noise by logarithmic transformation. Then the low-frequency laser multiplicative speckle noise is filtered by the high-pass filter, and the high-frequency demodulated signal is retained. The logarithmic inverse transform is used to obtain the laser echo demodulation signal after the multiplicative speckle noise has been filtered out. Next, the phase random disturbance of atmosphere in laser echo demodulated signal is suppressed by phase closure technology and the imaging spectrum component is reconstructed by the spectrum iterative reconstruction method. Then the high resolution image is obtained by spectrum component inverse Fourier transform. Finally, the effect of background additive noise on the image quality is suppressed by the sparse base tracking theory. The simulated and outdoor experiment result are used to verify the denoising effect and image quality enhancement effect of the composite de-noising method. Compared with the existing single denoising method, the composite denoising method is shown to be able to effectively eliminate laser multiplicative speckle noise and background additive noise at one time. The proposed method can improve image contrast and promote the Strehl ratio of imaging quality in a coherent imaging system. It provides a theoretical basis for improving imaging quality and denosing laser multiplicative speckle noise and background additive noise in coherent field imaging system.
入藏号: WOS:000460734800018
ISSN: 1000-3290
________________________________________
第 236 条,共 344 条
标题: Multidimensional Manipulation of Photonic Spin Hall Effect with a Single-Layer Dielectric Metasurface
作者: Li, SQ (Li, Siqi); Li, XY (Li, Xingyi); Wang, GX (Wang, Guoxi); Liu, S (Liu, Sheng); Zhang, LX (Zhang, Lingxuan); Zeng, C (Zeng, Chao); Wang, LR (Wang, Leiran); Sun, QB (Sun, Qibing); Zhao, W (Zhao, Wei); Zhang, WF (Zhang, Wenfu)
来源出版物: ADVANCED OPTICAL MATERIALS 卷: 7 期: 5 文献号: 1801365 DOI: 10.1002/adom.201801365 出版年: MAR 5 2019
摘要: The photonic spin Hall effect, originating from photonic spin-orbit interactions, has attracted considerable research interest due to its potential for applications in spin-controlled nanophotonics. However, most research efforts have focused only on 1D modulation, including transverse or longitudinal spin-dependent splitting. Here, a novel method is proposed for multidimensional spin-dependent splitting on a single-layer dielectric metasurface. Due to the interplay of the Pancharatnam-Berry phase and dynamic phase, the longitudinal focusing and transverse shifting of the different spin state photons can be simultaneously achieved. Moreover, the conjugated characteristic of the modulated phases of Pancharatnam-Berry phase metasurfaces for different spin photons can be broken, and both symmetric and asymmetric transverse spin-dependent splitting are obtained with the proposed method. This method can be used for the multidimensional and flexible manipulation of spin photons and has potential in spin-controlled nanophotonics, ranging from optical communication to beam shaping and optical sensors.
入藏号: WOS:000460336000009
ISSN: 2195-1071
________________________________________
第 237 条,共 344 条
标题: Optical properties and applications of molybdenum disulfide/SiO2 saturable absorber fabricated by sol-gel technique
作者: Lv, RD (Lv, Ruidong); Chen, ZD (Chen, Zhendong); Liu, SC (Liu, Sicong); Wang, J (Wang, Jiang); Li, YF (Li, Yongfang); Wang, YG (Wang, Yonggang); Wang, YS (Wang, Yishan)
来源出版物: OPTICS EXPRESS 卷: 27 期: 5 页: 6348-6356 DOI: 10.1364/OE.27.006348 出版年: MAR 4 2019
摘要: We investigate a new type of molybdenum disulfide (MoS2)-doped sol-gel glass saturable absorber (SA) fabricated by sol-gel technique. The reagents used for the sol-gel glass contain Tetraethyl orthosilicate (TEOS), ethanol, water, and hydrochloric acid. Different from the traditional ways of fabricating SAs, the MoS2 in our method is encapsulated by inorganic sol-gel glass instead of polymer compound with low laser damage resistance, which greatly increases the optical damage threshold of MoS2 SA. The MoS2-doped sol-gel glass as an SA is experimentally demonstrated in a passively mode-locked ytterbium-doped fiber laser (YDFL). Stable mode-locked pulse trains are successfully generated in the normal dispersion regime with a pulse width of 13.8 ps and the average output power of 34.6 mW. The fluctuation of the central wavelength and spectral bandwidth is as low as 0.9% in one week, which indicates that the mode-locking state has good environmental stability. To the best of our knowledge, it is the first example of sol-gel glass SA for ultrafast pulses generated in YDFL, which potentially gives a new approach to improve optical damage threshold and long-term working stability for broadband absorbers. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000460170000036
PubMed ID: 30876221
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Jang                  0000-0002-3969-9459

ISSN: 1094-4087
________________________________________
第 238 条,共 344 条
标题: Truncated Gaussian-Bessel beams for short-pulse processing of small-aspect-ratio micro-channels in dielectrics
作者: Liu, X (Liu, X.); Li, Q (Li, Q.); Sikora, A (Sikora, A.); Sentis, M (Sentis, M.); Uteza, O (Uteza, O.); Stoian, R (Stoian, R.); Zhao, W (Zhao, W.); Cheng, G (Cheng, G.); Sanner, N (Sanner, N.)
来源出版物: OPTICS EXPRESS 卷: 27 期: 5 页: 6996-7008 DOI: 10.1364/OE.27.006996 出版年: MAR 4 2019
摘要: In order to control the length of micro-channels ablated at the surface of dielectrics, we use annular filtering apertures for tailoring the depth of focus of micrometric Gaussian-Bessel beams. We identify experimentally and numerically the appropriate beam truncation that promotes a smooth axial distribution of intensity with a small elongation, suitable for processing micro-channels of small aspect ratio. Single-shot channel fabrication is demonstrated on the front surface of a fused silica sample, with sub-micron diameter, high-quality opening, and depth of few micrometers, using 1 ps low-energy (< 0.45 mu J) pulse. Finally, we realize 10 x 10 matrices of densely packed channels with aspect ratio similar to 5 and a spatial period down to 1.5 mu m, as a prospective demonstration of direct laser fabrication of 2D photonic-crystal structures. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000460170000088
PubMed ID: 30876273
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Qingfeng         V-5485-2019         0000-0003-2063-3510
Stoian, Razvan                  0000-0003-2107-9515

ISSN: 1094-4087
________________________________________
第 239 条,共 344 条
标题: A survey on sentiment analysis and opinion mining for social multimedia
作者: Li, ZH (Li, Zuhe); Fan, YY (Fan, Yangyu); Jiang, B (Jiang, Bin); Lei, T (Lei, Tao); Liu, WH (Liu, Weihua)
来源出版物: MULTIMEDIA TOOLS AND APPLICATIONS 卷: 78 期: 6 页: 6939-6967 DOI: 10.1007/s11042-018-6445-z 出版年: MAR 2019
摘要: Social media sentiment analysis (also known as opinion mining) which aims to extract people's opinions, attitudes and emotions from social networks has become a research hotspot. Conventional sentiment analysis concentrates primarily on the textual content. However, multimedia sentiment analysis has begun to receive attention since visual content such as images and videos is becoming a new medium for self-expression in social networks. In order to provide a reference for the researchers in this active area, we give an overview of this topic and describe the algorithms of sentiment analysis and opinion mining for social multimedia. Having conducted a brief review on textual sentiment analysis for social media, we present a comprehensive survey of visual sentiment analysis on the basis of a thorough investigation of the existing literature. We further give a summary of existing studies on multimodal sentiment analysis which combines multiple media channels. We finally summarize the existing benchmark datasets in this area, and discuss the future research trends and potential directions for multimedia sentiment analysis. This survey covers 100 articles during 2008-2018 and categorizes existing studies according to the approaches they adopt.
入藏号: WOS:000468529700024
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Zuhe                  0000-0002-2511-3226

ISSN: 1380-7501
eISSN: 1573-7721
________________________________________
第 240 条,共 344 条
标题: Generation of dark solitons in erbium-doped fiber laser based on black phosphorus nanoparticles
作者: Liu, JY (Liu, Jianyou); Zhao, FY (Zhao, Fengyan); Wang, HS (Wang, Hushan); Zhang, W (Zhang, Wei); Hu, XH (Hu, Xiaohong); Li, XH (Li, Xiaohui); Wang, YS (Wang, Yishan)
来源出版物: OPTICAL MATERIALS 卷: 89 页: 100-105 DOI: 10.1016/j.optmat.2018.12.055 出版年: MAR 2019
摘要: We demonstrate the generation of dark solitons (DSs) in erbium-doped fiber (EDF) laser based on black phosphorus nanoparticles (BPNPs) for the first time. The side-polished fiber deposited with BPNPs is embedded into the laser to enhance the birefringence and nonlinearity of the laser cavity. In the paper, the saturable absorption property of BPNPs with an optical modulation depth of 5.7% and a saturable intensity of 21.7 MW/cm(2) are experimentally illustrated. After inserting the BPNPs saturable absorber (SA) into EDF laser, the DSs with repetition rate of 14.68 MHz are obtained at a pump power of 90 mW. Our results prove that the BPNPs are the promising candidate materials for generating DSs in EDF laser.
入藏号: WOS:000465509800013
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xiaohui         J-9580-2012         0000-0002-5600-3820

ISSN: 0925-3467
eISSN: 1873-1252
________________________________________
第 241 条,共 344 条
标题: The infrared moving target extraction and fast video reconstruction algorithm
作者: Qiu, S (Qiu, Shi); Tang, Y (Tang, Ying); Du, Y (Du, Yun); Yang, S (Yang, Song)
来源出版物: INFRARED PHYSICS & TECHNOLOGY 卷: 97 页: 85-92 DOI: 10.1016/j.infrared.2018.11.025 出版年: MAR 2019
摘要: Due to the problems of targets submerged to the background, which could easily produce ghosts, and hard complete extraction of dim targets in the surveillance video, we propose the moving target extraction and fast video reconstruction algorithm in accord with visual principle. The sample selection strategy of VIBE algorithm is improved to alleviate the errors of pixel classification. The infrared imaging features are fused to suppress the artifact. A regional growth mechanism is established to extract and store moving targets and pure background regions, and according to the characteristics of video surveillance, it is the first to establish the mapping mechanism of target, background and video to propose the fast video reconstruction algorithm. The experiment shows that the algorithm can extract the moving target completely, establish the pure background in a variety of complex conditions, and greatly reduce the storage room of the surveillance video.
入藏号: WOS:000465060100014
ISSN: 1350-4495
eISSN: 1879-0275
________________________________________
第 242 条,共 344 条
标题: Aberration correction method based on double-helix point spread function
作者: Wang, ZJ (Wang, Zhaojun); Cai, YN (Cai, Yanan); Liang, YS (Liang, Yansheng); Dan, D (Dan, Dan); Yao, BL (Yao, Baoli); Lei, M (Lei, Ming)
来源出版物: JOURNAL OF BIOMEDICAL OPTICS 卷: 24 期: 3 文献号: 031005 DOI: 10.1117/1.JBO.24.3.031005 出版年: MAR 2019
摘要: Point spread function (PSF) engineering has met with lots of interest in various optical imaging techniques, including super-resolution microscopy, microparticle tracking, and extended depth-of-field microscopy. The intensity distributions of the modified PSFs often suffer from deteriorations caused by system aberrations, which greatly degrade the image contrast, resolution, or localization precision. We present an aberration correction method using a spiral-phase-based double-helix PSF as an aberration indicator, which is sensitive and quantitatively correlated to the spherical aberration, coma, and astigmatism. Superior to the routine iteration-based correction methods, the presented approach is iteration-free and the aberration coefficients can be directly calculated with the measured parameters, relieving the computing burden. The validity of the method is verified by both examining the intensity distribution of the conventional Gaussian PSF in three dimensions and observing muntjac skin fibroblast cells. This iteration-free correction method has a potential application in PSF engineering systems equipped with a spatial light modulator. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
入藏号: WOS:000463886200008
PubMed ID: 30182579
ISSN: 1083-3668
eISSN: 1560-2281
________________________________________
第 243 条,共 344 条
标题: Design Analysis of a Passive Buffer System for Space-Assembled Segmented Mirrors
作者: Li, XP (Li, Xupeng); Wang, W (Wang, Wei); Shi, JF (Shi, Jinfeng); Qu, YJ (Qu, Yanjun); Fan, XW (Fan, Xuewu)
来源出版物: APPLIED SCIENCES-BASEL 卷: 9 期: 5 文献号: 985 DOI: 10.3390/app9050985 出版年: MAR 1 2019
摘要: This paper presents a passive buffer system of connection mechanism for space-assembled segmented mirrors. The purpose of assembling telescope in space is to overcome the limits of launch volume and mass to support ever increasing aperture sizes. Using this buffer system, the docking impact between two mirror segments can be alleviated effectively. In this paper, first, a design methodology called "double-elastic contact model" is developed. Then, the design details and operation principle of the connection mechanism, are presented to validate the passive buffer system. Finally, by comparing the traditional docking system, the simulated results of dynamic performance show that the proposed buffer system can absorb the impact energy effectively and is considerably suitable for assembling the space optical system.
入藏号: WOS:000462504400172
ISSN: 2076-3417
________________________________________
第 244 条,共 344 条
标题: Photon-Counting Underwater Optical Wireless Communication for Reliable Video Transmission Using Joint Source-Channel Coding Based on Distributed Compressive Sensing
作者: Hong, Z (Hong, Zhu); Yan, QR (Yan, Qiurong); Li, ZH (Li, Zihang); Zhan, T (Zhan, Ting); Wang, YH (Wang, Yuhao)
来源出版物: SENSORS 卷: 19 期: 5 文献号: 1042 DOI: 10.3390/s19051042 出版年: MAR 1 2019
摘要: To achieve long-distance underwater optical wireless communication, a single photon detector with single photon limit sensitivity is used to detect the optical signal at the receiver. The communication signal is extracted from the discrete single photon pulses output from the detector. Due to fluctuation of photon flux and quantum efficiency of photon detection, long-distance underwater optical wireless communication has the characteristics that the link is easily interrupted, the bit error rate is high, and the burst error is large. To achieve reliable video transmission, a joint source-channel coding scheme based on residual distributed compressive video sensing is proposed for the underwater photon counting communication system. Signal extraction from single photon pulses, data frame and data verification are specifically designed. This scheme greatly reduces the amount of data at the transmitter, transfers the computational complexity to the decoder in receiver, and enhances anti-channel error ability. The experimental results show that, when the baud rate was 100 kbps and the average number of photon pulses per bit was 20, the bit error rate (BER) was 0.0421 and video frame could still be restored clearly.
入藏号: WOS:000462540400061
PubMed ID: 30823639
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yan, Qiurong                  0000-0003-4736-7435

ISSN: 1424-8220
________________________________________
第 245 条,共 344 条
标题: Microfiber interferometer integrated with Au nanorods for an all-fiber phase shifter and switch
作者: Yang, XH (Yang, Xinghua); Long, QL (Long, Qunlong); Liu, ZH (Liu, Zhihai); Zhang, Y (Zhang, Yu); Yang, J (Yang, Jun); Kong, DP (Kong, Depeng); Yuan, LB (Yuan, Libo); Oh, K (Oh, Kyunghwan)
来源出版物: OPTICS LETTERS 卷: 44 期: 5 页: 1092-1095 DOI: 10.1364/OL.44.001092 出版年: MAR 1 2019
摘要: All-fiber integrated phase shifters and optical switches have important applications in photonic devices, such as optical controlling, optical fiber sensing, and signal processing. In this Letter, for the first time to the best of our knowledge, we integrated the photothermal effect of a nanomaterial based on gold nanorods (GNRs) and a microfiber interferometer to realize a compact all-optical fiber phase shifter. GNRs surrounding the microfiber were excited by near-infrared light via the evanescent interaction, subsequently releasing the heat through the photothermal effect. Then, the refractive index around the microfiber was varied to shift the interference dips in a reversible manner. Experimentally, a spectral shift efficiency of 0.16 nm/mW near the wavelength of 1550 nm was obtained using an excitation laser at the wavelength of 808 nm. The device also provided an all-optical switching with the modulation depth of 76.4%. The proposed GNR-based all-fiber device can provide high potentials in all-optical signal control applications. (c) 2019 Optical Society of America
入藏号: WOS:000460109200008
PubMed ID: 30821778
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yang, jun         G-4446-2014         0000-0002-6805-4289

ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 246 条,共 344 条
标题: Purely Kerr nonlinear model admitting flat-top solitons
作者: Zeng, LW (Zeng, Liangwei); Zeng, JH (Zeng, Jianhua); Kartashov, YV (Kartashov, Yaroslav V.); Malomed, BA (Malomed, Boris A.)
来源出版物: OPTICS LETTERS 卷: 44 期: 5 页: 1206-1209 DOI: 10.1364/OL.44.001206 出版年: MAR 1 2019
摘要: We elaborate one- and two-dimensional (1D and 2D) models of media with self-repulsive cubic nonlinearity, whose local strength is subject to spatial modulation that admits the existence of flat-top solitons of various types, including fundamental ones, 1D multipoles, and 2D vortices. Previously, solitons of this type were only produced by models with competing nonlinearities. The present setting may be implemented in optics and Bose-Einstein condensates. The 1D version gives rise to an exact analytical solution for stable flat-top solitons, and generic families may be predicted by means of the Thomas-Fermi approximation. Stability of the obtained flat-top solitons is analyzed by means of the linear-stability analysis and direct simulations. Fundamental solitons and 1D multipoles with k=1 and 2 nodes, as well as vortices with winding number m=1, are completely stable. For multipoles with k >= 3 and vortices with m >= 2, alternating stripes of stability and instability are identified in their parameter spaces. (c) 2019 Optical Society of America
入藏号: WOS:000460109200035
PubMed ID: 30821749
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zeng, Liangwei         P-1946-2019         0000-0001-9603-1845
ceng, jian hua                  0000-0003-0189-1856
Kartashov, Yaroslav                  0000-0001-8692-982X

ISSN: 0146-9592
eISSN: 1539-4794
________________________________________
第 247 条,共 344 条
标题: Near-infrared optical properties and thermal stability of proton-implanted Er3+/Yb3+ co-doped silicate glass waveguides
作者: Chen, JY (Chen, Jing-Yi); Lv, JY (Lv, Jing-Yan); Wang, ZY (Wang, Zhong-Yue); Lin, SB (Lin, She-Bao); Guo, HT (Guo, Hai-Tao); Liu, CX (Liu, Chun-Xiao)
来源出版物: RESULTS IN PHYSICS 卷: 12 页: 357-360 DOI: 10.1016/j.rinp.2018.11.098 出版年: MAR 2019
摘要: We have fabricated optical waveguides in Er3+/Yb3+ co-doped silicate glasses by the hydrogen ion implantation, which resulted in a higher refractive index region with a width of around 6.0 mu m to guide near-infrared light as a waveguide core. The thermal stability of the waveguide structure was obtained by the annealing at 200 degrees C for 60 min. The refractive index changes before and after annealing were characterized by the prism coupling method at 1.539 mu m. The measured refractive index corresponded well with that of the calculated mode by a numerical analysis based on the RCM. The cross-sectional image of the proton-implanted waveguide was recorded by an optical microscope. The propagation properties of 1.539-mu m light in the waveguiding layer of the structure was calculated by the FD-BPM. Considering the importance of waveguide structure in the Er3+/Yb3+ co-doped silicate glass for integrated photonic components, the thermal-stable proton-implanted waveguide can be a starting point for the development of on-chip devices in the near-infrared region.
入藏号: WOS:000460704700047
ISSN: 2211-3797
________________________________________
第 248 条,共 344 条
标题: Method for Mueller matrix acquisition based on a division-of-aperture simultaneous polarimetric imaging technique
作者: Ju, HJ (Ju, Haijuan); Ren, LY (Ren, Liyong); Liang, J (Liang, Jian); Qu, ES (Qu, Enshi); Bai, ZF (Bai, Zhaofeng)
来源出版物: JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 卷: 225 页: 39-44 DOI: 10.1016/j.jqsrt.2018.12.020 出版年: MAR 2019
摘要: The Mueller matrix is an important parameter in the field of polarization optics, and how to measure it efficiently and accurately becomes considerably significant for its practical applications. In this paper, for the first time to our knowledge, we propose a new method for Mueller matrix acquisition based on a division-of-aperture simultaneous polarimetric imaging technique. Different from the traditional method where, for obtaining the 16 elements of the Mueller matrix, a 16-times-measurement must be conducted by jointly changing the states of polarization (SOPS) of the input and output lights, while in our method it is enough by just changing the SOPs of the input light 4 times. This time-saving and easy-calculating feature is owing to our specific polarimetric camera, where a full-Stokes vector is obtained easily since 3 linear SOPs (0 degrees, 45 degrees, 90 degrees) and 1 circular SOP can be recorded simultaneously by spatially sharing the same detector. To simply verify the effectiveness of our method, a specific polarization device patched by 8 sub-polarizers is chosen as the sample to be measured. Experimental results show that they are consistent with the theoretical results, both in the Mueller matrix and the corresponding images. We predict that this method for Mueller matrix acquisition can get wide potential applications for rapid identifications in biomedicine and material science. (C) 2018 Elsevier Ltd. All rights reserved.
入藏号: WOS:000460495100005
会议名称: 1st International Workshop on Advancement of Polarimetric Observations - Calibration and Improved Aerosol Retrievals (APOLO)
会议日期: OCT 24-27, 2017
会议地点: Hefei, PEOPLES R CHINA
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
ren, li yong         F-5518-2014         0000-0002-7547-7511

ISSN: 0022-4073
eISSN: 1879-1352
________________________________________
第 249 条,共 344 条
标题: The image stitching algorithm based on aggregated star groups
作者: Qiu, S (Qiu, Shi); Zhou, DM (Zhou, Dongmei); Du, Y (Du, Yun)
来源出版物: SIGNAL IMAGE AND VIDEO PROCESSING 卷: 13 期: 2 页: 227-235 DOI: 10.1007/s11760-018-1349-y 出版年: MAR 2019
摘要: The star map has the characteristics of large amount of data and wide angle of view. The star points are displayed as limited pixels on the image and easy to get disturbed by noise, so it is difficult to build a feature model to obtain the complete star map. In this paper, we have revised the OTSU algorithm and extracted the star points accurately according to the characteristics of star point pixels. We are inspired by the idea of compressed perception to break the local spatial relationship of stars, construct the aggregated star group model of relative relationship of local stars, realize the matching and construct the extended model to realize the stitching of wide angle star images. In order to meet the requirements of efficient transmission and storage in the air or on the ground, we have proposed the algorithm of star point storage and mapping. We set up a database with 600 frames of real star images from CCD camera and 600 frames of simulated star images, and the experiments show that our algorithm can compress the data and realize the star image stitching.
入藏号: WOS:000459989400003
ISSN: 1863-1703
eISSN: 1863-1711
________________________________________
第 250 条,共 344 条
标题: Compact low-noise passively mode-locked Er-doped femtosecond all-fiber laser with 2.68 GHz fundaments repetition rate
作者: Song, JZ (Song, Jiazheng); Wang, HS (Wang, Hushan); Huang, XN (Huang, Xinning); Hu, XH (Hu, Xiaohong); Zhang, T (Zhang, Ting); Wang, YS (Wang, Yishan); Liu, YS (Liu, Yuanshan); Zhang, JG (Zhang, Jianguo)
来源出版物: APPLIED OPTICS 卷: 58 期: 7 页: 1733-1738 DOI: 10.1364/AO.58.001733 出版年: MAR 1 2019
摘要: A passively mode-locked Er-doped fiber laser with a fundamental repetition rate of 2.68 GHz is reported. The oscillator operating at a central wavelength of 1558.35 nm has a compact, robust structure and low-noise performance. The timing jitter integrated from 30 MHz down to 300 Hz is 82.5 fs, and the timing jitter performance is analyzed based on the theory model. The amplification and compression of the high repetition rate optical pulses are also investigated. After a three-stage amplifier, the average power is boosted to 430 mW. Meanwhile, based on the nonlinear self-phase modulation effect, the spectral bandwidth is broadened from 7.56 to 19.2 nm, and the corresponding pulse width is compressed to 244 fs. (C) 2019 Optical Society of America
入藏号: WOS:000460120600025
PubMed ID: 30874208
ISSN: 1559-128X
eISSN: 2155-3165

第 251 条,共 344 条
标题: Remote Sensing Image Scene Classification Using Rearranged Local Features
作者: Yuan, Y (Yuan, Yuan); Fang, J (Fang, Jie); Lu, XQ (Lu, Xiaoqiang); Feng, YC (Feng, Yachuang)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 3 页: 1779-1792 DOI: 10.1109/TGRS.2018.2869101 出版年: MAR 2019
摘要: Remote sensing image scene classification is a fundamental problem, which aims to label an image with a specific semantic category automatically. Recently, deep learning methods have achieved competitive performance for remote sensing image scene classification, especially the methods based on a convolutional neural network (CNN). However, most of the existing CNN methods only use feature vectors of the last fully connected layer. They give more importance to global information and ignore local information of images. It is common that some images belong to different categories, although they own similar global features. The reason is that the category of an image may be highly related to local features, other than the global feature. To address this problem, a method based on rearranged local features is proposed in this paper. First, outputs of the last convolutional layer and the last fully connected layer are employed to depict the local and global information, respectively. After that, the remote sensing images are clustered to several collections using their global features. For each collection, local features of an image are rearranged according to their similarities with local features of the cluster center. In addition, a fusion strategy is proposed to combine global and local features for enhancing the image representation. The proposed method surpasses the state of the arts on four public and challenging data sets: UC-Merced, WHU-RS19, Sydney, and AID.
入藏号: WOS:000460321300043
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Fang, Jie                  0000-0002-8325-3905
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 252 条,共 344 条
标题: Effect of Ba(PO3)(2) addition on the optical properties of Tm3+-doped fluorophosphate glasses
作者: Sun, X (Sun, Xin); She, JB (She, Jiangbo); Li, XH (Li, Xiaohui); Lu, M (Lu, Min); Wang, PF (Wang, Pengfei); Li, DD (Li, Dongdong)
来源出版物: OPTICAL MATERIALS EXPRESS 卷: 9 期: 3 页: 1233-1245 DOI: 10.1364/OME.9.001233 出版年: MAR 1 2019
摘要: Tm3+-doped fluorophosphate glasses with varying Ba(PO3)(2) content were prepared by the melt quenching technique and their thermal and optical properties were investigated by studying differential scanning calorimetry, Raman spectra, fluorescence spectra, decay curves, transmission and absorption spectra. The Judd-Ofelt theory was applied to calculate the intensity parameters of the resultant glass. The glass forming criterion was obtained to be 146 degrees C. The gain coefficient and fluorescence lifetime of Tm3+-doped fluorophosphate glass with 20 mol% Ba(PO3)(2) were 3.045 x 10(-21) cm(2) x ms and 0.406 ms, respectively, which are the highest value among the fluorophosphate glasses with similar components to the best of our knowledge. These results clearly indicate that the prepared fluorophosphate glass is an attractive candidate for 2 mu m lasers and as a gain media for optical amplifier applications. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000460134500027
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xiaohui         J-9580-2012         0000-0002-5600-3820

ISSN: 2159-3930
________________________________________
第 253 条,共 344 条
标题: Sulfide treatment passivation of mid-/long-wave dual-color infrared detectors based on type-II InAs/GaSb superlattices
作者: Guo, CY (Guo, Chunyan); Jiang, Z (Jiang, Zhi); Jiang, DW (Jiang, Dongwei); Wang, GW (Wang, Guowei); Xu, YQ (Xu, Yingqiang); Wang, T (Wang, Tao); Tian, JS (Tian, Jinshou); Wu, ZX (Wu, Zhaoxin); Niu, ZC (Niu, Zhichuan)
来源出版物: OPTICAL AND QUANTUM ELECTRONICS 卷: 51 期: 3 文献号: 73 DOI: 10.1007/s11082-019-1779-y 出版年: MAR 2019
摘要: The surface passivation of mid-/long-wave dual-color infrared detectors based on type-II InAs/GaSb superlattices(T2SLs) photodetectors employing diverse voltage and current conditions of sulfide treatment passivation was presented. The superlattices were grown on GaSb substrate by molecular beam epitaxy technology. The circle pixel devices in the diameter of 200m with 5m at mid-infrared and 14m at long-infrared 100% cutoff wavelength were fabricated. Compared to only SiO2 encapsulation passivation and unpassivated detectors, the dark current density, which takes into account surface leakage current, was reduced by approximately three orders of magnitude and the R0A-product was six times higher by sulfide treatment. Besides, detectors passivated through 22V 15mA sulfur treated, the responsivity of was 0.95A/W and QE was 0.44 at 2.6m. As for the wavelength of 5.3m, the responsivity and QE were 1.95 A/W and 0.45 severally.
入藏号: WOS:000460035600006
ISSN: 0306-8919
eISSN: 1572-817X
________________________________________
第 254 条,共 344 条
标题: Co-occurrence matching of local binary patterns for improving visual adaption and its application to smoke recognition
作者: Yuan, FN (Yuan, Feiniu); Shi, JT (Shi, Jinting); Xia, X (Xia, Xue); Huang, QH (Huang, Qinghua); Li, XL (Li, Xuelong)
来源出版物: IET COMPUTER VISION 卷: 13 期: 2 特刊: SI 页: 178-187 DOI: 10.1049/iet-cvi.2018.5164 出版年: MAR 2019
摘要: It is challenging to recognize smoke from visual scenes due to large variations of smoke colors, textures and shapes. To improve robustness, we propose a novel feature extraction method based on similarity and dissimilarity matching measures of Local Binary Patterns (LBP). Given two bit-sequences of an LBP code pair, the similarity and dissimilarity matching measures are defined as the ratios of the 1-1 bitwise matching number to the 0-0 bitwise matching number and the 1-0 number to the 0-1 number, respectively. To capture local code variations, we calculate the measures between LBP codes of a center pixel and its neighbors. Then we compare each measure with its global mean to propose Similarity Matching based Local Binary Patterns (SMLBP) and Dissimilarity Matching based Local Binary Patterns (DMLBP). Since SMLBP and DMLBP extract spatial variations of the 1st order LBP codes, they actually represent the 2nd order variations of pixel values. Furthermore, we adopt different mapping modes and multi-scale neighborhoods to obtain rotation and scale invariances. Finally, we concatenate the histograms of LBP, SMLBP and DMLBP to generate a feature vector containing 1st and 2nd order information. Experiments show that our method obviously outperforms existing methods.
入藏号: WOS:000459454900013
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         

ISSN: 1751-9632
eISSN: 1751-9640
________________________________________
第 255 条,共 344 条
标题: Separation of optical angular momentum flux
作者: Yan, SH (Yan, Shaohui); Li, MM (Li, Manman); Yao, BL (Yao, Baoli)
来源出版物: JOURNAL OF OPTICS 卷: 21 期: 3 文献号: 035606 DOI: 10.1088/2040-8986/ab02d5 出版年: MAR 2019
摘要: We present an approach to separating the angular momentum (AM) flux of monochromatic light into its spin and orbital parts based on a symmetrized AM tensor <(M) over bar >. When considering the AM flux for a light beam through its cross section and that for an outgoing wave through a spherical surface in the far-field zone, the separation gives the desired results: the spin/orbital AM flux equals the integral of spin/orbital AM density times some weighting factor accounting for energy flux. When applied to Bessel beams, the obtained spin and orbital AM fluxes are exactly the same as those given by the paper (2014 New J. Phys. 16 093037) based on the canonical AM tensor separation. Furthermore, from the spin AM flux integral, the divergence-free spin AM tensor <(S) over bar > can be identified. We define the orbital AM tensor to be the difference between the total AM tensor <(M) over bar > and <(S) over bar >. Since <(M) over bar > is divergence-free, the integral for either spin and orbital AM flux, can be made on any closed surface.
入藏号: WOS:000459148500001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yan, Shaohui                  0000-0003-3983-7206

ISSN: 2040-8978
eISSN: 2040-8986
________________________________________
第 256 条,共 344 条
标题: Improving the image reconstruction quality of compressed ultrafast photography via an augmented Lagrangian algorithm
作者: Yang, CS (Yang, Chengshuai); Qi, DL (Qi, Dalong); Cao, FY (Cao, Fengyan); He, YL (He, Yilin); Wang, X (Wang, Xing); Wen, WL (Wen, Wenlong); Tian, JS (Tian, Jinshou); Jia, TQ (Jia, Tianqing); Sun, ZR (Sun, Zhenrong); Zhang, SA (Zhang, Shian)
来源出版物: JOURNAL OF OPTICS 卷: 21 期: 3 文献号: 035703 DOI: 10.1088/2040-8986/ab00d9 出版年: MAR 2019
摘要: Compressed ultrafast photography (CUP) has been shown to be a powerful tool to measure ultrafast dynamic scenes. In previous studies, CUP used a two-step iterative shrinkage/thresholding (TwIST) algorithm to reconstruct three-dimensional image information. However, the image reconstruction quality greatly depended on the selection of the penalty parameter, which caused the reconstructed images to be unable to be correctly determined if the ultrafast dynamic scenes were unknown in advance. Here, we develop an augmented Lagrangian (AL) algorithm for the image reconstruction of CUP to overcome the limitation of the TwIST algorithm. Our numerical simulations and experimental results show that, compared to the TwIST algorithm, the AL algorithm is less dependent on the selection of the penalty parameter, and can obtain higher image reconstruction quality. This study solves the problem of the image reconstruction instability, which may further promote the practical applications of CUP.
入藏号: WOS:000458924300001
ISSN: 2040-8978
eISSN: 2040-8986
________________________________________
第 257 条,共 344 条
标题: Large-scale and uniform Raman substrate of coupled Ag grating with Ag triangle arrays
作者: Li, KG (Li, Kuanguo); Liu, GJ (Liu, Guangju); Ghafoor, S (Ghafoor, Sonia); Dai, YQ (Dai, Yanqiu); Huang, WX (Huang, Wanxia); Zhang, FB (Zhang, Fabao); Lu, YH (Lu, Yonghua)
来源出版物: JOURNAL OF OPTICS 卷: 21 期: 3 文献号: 035005 DOI: 10.1088/2040-8986/ab0273 出版年: MAR 2019
摘要: Vertically coupled plasmonic structures have been widely used in optical applications due to its enhanced electromagnetic fields in the gaps between metallic nanostructures. In this paper, a large-scale vertically coupled structure composed of the Ag triangle array (AgTA) on Ag grating separated by a nanometric dielectric layer is fabricated by nanosphere lithography incorporated with photolithography. Thanks to the effective surface plasmon polaritons excitation on the Ag grating, a significant surface enhanced Raman spectroscopy (SERS) effect arises from a strongly enhanced local electric field within the tiny gaps between the AgTA and Ag grating, which is verified by experiment and theoretical simulations. The as-proposed SERS substrate exhibits a nice uniformity with the relative standard deviation of about 10.5%, leading to excellent reliability for Raman detection. The simple fabrication of the large-area, productive, and inexpensive vertically coupled plasmonic structure can be a potential candidate for SERS applications.
入藏号: WOS:000458922900001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
lu, yonghua         G-8396-2011         
Li, Kuanguo                  0000-0003-3296-2012

ISSN: 2040-8978
eISSN: 2040-8986
________________________________________
第 258 条,共 344 条
标题: Enhanced self-phase modulation effect: an effective method of generating high average and peak power femtosecond laser pulses
作者: Lv, ZG (Lv, Zhiguo); Yang, Z (Yang, Zhi); Song, DD (Song, DongDong); Li, F (Li, Feng); Yang, Y (Yang, Yang); Yang, XJ (Yang, Xiaojun); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Li, QL (Li, Qianglong)
来源出版物: LASER PHYSICS LETTERS 卷: 16 期: 3 文献号: 035110 DOI: 10.1088/1612-202X/aaff49 出版年: MAR 2019
摘要: This work experimentally explores the important application of the enhanced self-phase modulation (SPM) effect for the generation of high average power and high peak power femtosecond laser pulses in an all-fiber mode-locked laser oscillator pumped by a single-mode laser diode. Depending on the utilization of a section of nonlinear spectral broadening fiber with a 4.2 mu m mode field diameter (MFD) and the optimization of the polarization-maintaining (PM) fiber length in a polarization-based all-fiber Lyot filter, the oscillator delivers 350 mW of average power at a 46.2 MHz repetition rate, resulting in 7.5 nJ pulse energy. The laser produces SPM-broadened spectrum and the spectrum features symmetrical multi-peak distribution. The resulting compressed pulse duration and average power are 107 fs and 271 mW, respectively, which corresponds to 54.8 kW of peak power. Additionally, comparative experiments have also been performed by replacing the nonlinear spectral broadening fiber with equal-length standard fiber with 6.2 mu m MFD and shortening the length of the 45 degrees aligned PM fiber of the all-fiber polarization-based Lyot filter, respectively. The presented experimental scheme demonstrates a notable improvement in terms of average and peak power compared to conventional experimental methods. Simultaneously, the experimental scheme also shows that the enhanced SPM effect in a mode-locked fiber laser oscillator has important application value for minimizing pulse duration and lowering the mode-locking threshold.
入藏号: WOS:000458531600002
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
qianglong, li         V-6278-2019         

ISSN: 1612-2011
eISSN: 1612-202X
________________________________________
第 259 条,共 344 条
标题: Preparation and thermal optimization of the proton-implanted high-gain Nd3+-doped laser glass waveguide
作者: Chen, JY (Chen, Jing-Yi); Wang, Y (Wang, Yi); Wang, ZM (Wang, Zhi-Ming); Zhang, LL (Zhang, Liao-Lin); Guo, HT (Guo, Hai-Tao); Liu, CX (Liu, Chun-Xiao)
来源出版物: JAPANESE JOURNAL OF APPLIED PHYSICS 卷: 58 期: 3 文献号: 032002 DOI: 10.7567/1347-4065/aafb49 出版年: MAR 1 2019
摘要: In this work, the high-gain Nd3+-doped laser glass was chosen as the target material, and the optical waveguide was formed on the glass by the H+ ion implantation under the conditions of a 8.0 x 10(16)-ions cm(-2) fluence and a 0.4 MeV energy. The post-annealing at 200 degrees C for 1 h was applied to improve the optical quality of the waveguide. A metallographic microscope was used to detect changes in morphology caused by implanted ions in the high-gain Nd3+-doped laser glass. The characteristics of the ion-implanted high-gain Nd3+-doped laser glass optical waveguide, such as the dark-mode profiles and the near-field intensity distributions, were measured by experimental instruments including a prism coupler and an end-coupling system. The effects of nuclear energy loss of implanted ions on the refractive index variation of the substrate were analyzed by the reflectivity calculation method. The interaction mechanism of implanted protons with the high-gain Nd3+-doped laser glass was discussed by the SRIM 2013 code. It lays a theoretical and experimental basis for the development of high-gain Nd3+-doped glass waveguide lasers and amplifiers. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000457725800001
ISSN: 0021-4922
eISSN: 1347-4065
________________________________________
第 260 条,共 344 条
标题: Chemical etching mechanisms and crater morphologies pre-irradiated by temporally decreasing pulse trains of femtosecond laser
作者: Du, K (Du, Kun); Jiang, L (Jiang, Lan); Li, XW (Li, Xiaowei); Zhang, H (Zhang, Hao); Wang, AD (Wang, Andong); Yao, ZL (Yao, Zhulin); Pan, CJ (Pan, Changji); Wang, Z (Wang, Zhi); Li, M (Li, Ming); Grigoropoulos, CP (Grigoropoulos, Costas P.); Lu, YF (Lu, Yongfeng)
来源出版物: APPLIED SURFACE SCIENCE 卷: 469 页: 44-49 DOI: 10.1016/j.apsusc.2018.10.272 出版年: MAR 1 2019
摘要: We report the influence of temporally decreasing pulse trains on femtosecond laser-induced chemical etching (FLICE) of fused silica. A systematic comparison of the unshaped pulse and decreasing pulse trains of femtosecond laser for FLICE was conducted, and the differences were interpreted using a plasma model. The results revealed that the decreasing pulse trains not only affected the etching efficiency but also affected the morphology of the etched crater. When an etched crater was pre-irradiated by decreasing pulse trains, it presented a funnel-like shape at the early stage of the etching process, which contrasted with the one pre-irradiated by unshaped pulse. At the later stage of the etching process, the funnel-like shape gradually disappeared, and the crater increased in size. Compared with the unshaped pulse under the same processing conditions, the decreasing pulse trains enhanced the etched crater volume by approximately 18 times. Theoretical calculations based on the plasma model indicated that the free-electron density generated using the unshaped pulse was much higher than that generated by the decreasing pulse trains in skin layer of the sample during the first few hundred femtoseconds. The high free-electron density increased the reflectivity in skin layer of the sample; thus, the tail part of the incident pulse was strongly reflected. Consequently, the laser energy deposition into the fused silica sample decreased, eventually led to a low etching efficiency.
入藏号: WOS:000454617200006
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhang, Hao                  0000-0001-7789-7248

ISSN: 0169-4332
eISSN: 1873-5584
________________________________________
第 261 条,共 344 条
标题: Discrete Spectral Hashing for Efficient Similarity Retrieval
作者: Hu, D (Hu, Di); Nie, FP (Nie, Feiping); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON IMAGE PROCESSING 卷: 28 期: 3 页: 1080-1091 DOI: 10.1109/TIP.2018.2875312 出版年: MAR 2019
摘要: To meet the required huge data analysis, organization, and storage demand, the hashing technique has got a lot of attention as it aims to learn an efficient binary representation from the original high-dimensional data. In this paper, we focus on the unsupervised spectral hashing due to its effective manifold embedding. Existing spectral hashing methods mainly suffer from two problems, i.e., the inefficient spectral candidate and intractable binary constraint for spectral analysis. To overcome these two problems, we propose to employ spectral rotation to seek a better spectral solution and adopt the alternating projection algorithm to settle the complex code constraints, which are therefore named as Spectral Hashing with Spectral Rotation and Alternating Discrete Spectral Hashing, respectively. To enjoy the merits of both methods, the spectral rotation technique is finally combined with the original spectral objective, which aims to simultaneously learn better spectral solution and more efficient discrete codes and is called as Discrete Spectral Hashing. Furthermore, the efficient optimization algorithms are also provided, which just take comparable time complexity to existing hashing methods. To evaluate the proposed three methods, extensive comparison experiments and studies are conducted on four large-scale data sets for the image retrieval task, and the noticeable performance beats several state-of-the-art spectral hashing methods on different evaluation metrics.
入藏号: WOS:000448657400003
PubMed ID: 30307862
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Nie, Feiping         B-3039-2012         
Nie, Feiping                  0000-0002-0871-6519

ISSN: 1057-7149
eISSN: 1941-0042
________________________________________
第 262 条,共 344 条
标题: Experimental demonstration of quasi-omni-directional transmitter for underwater wireless optical communication based on blue LED array and freeform lens
作者: Han, B (Han, Biao); Zhao, W (Zhao, Wei); Zheng, YQ (Zheng, Yunqiang); Meng, JC (Meng, Jiacheng); Wang, T (Wang, Tao); Han, Y (Han, Yi); Wang, W (Wang, Wei); Su, YL (Su, Yulong); Duan, T (Duan, Tao); Xie, XP (Xie, Xiaoping)
来源出版物: OPTICS COMMUNICATIONS 卷: 434 页: 184-190 DOI: 10.1016/j.optcom.2018.10.037 出版年: MAR 1 2019
摘要: In this paper, we propose a transmitter with 150 degrees divergence angle and more than 90% uniformity of radiation intensity for quasi-omni-directional underwater wireless optical communication (UWOC) by applying freeform lens into LED array. We demonstrate its performance under different transmitting directions with 19Mbps data rate and 8m communication distance in an experimental tank whose volume is 20mx20mx14m and attenuation coefficient is about 0.40m(-1). The result shows that the variation of bit error rate (BER) is about three orders of magnitude with the help of freeform lens when direction deviation angle is between -75 degrees and +75 degrees, which is reduced five orders compared with the situation without the lens. The presented result is useful to make it easier to establish communication link and improve the performance of UWOC system when transmitter direction shake exists. Also, it implies that we could apply different freeform lenses into LED array to reshape transmitting illumination according to different demands for UWOC application.
入藏号: WOS:000451445000031
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 263 条,共 344 条
标题: Is it possible to enlarge the trapping range of optical tweezers via a single beam?
作者: Li, XZ (Li, X. Z.); Ma, HX (Ma, H. X.); Zhang, H (Zhang, H.); Tang, MM (Tang, M. M.); Li, HH (Li, H. H.); Tang, J (Tang, J.); Wang, YS (Wang, Y. S.)
来源出版物: APPLIED PHYSICS LETTERS 卷: 114 期: 8 文献号: 081903 DOI: 10.1063/1.5083108 出版年: FEB 25 2019
摘要: For optical tweezers, a tiny focal spot of the trapping beam is necessary for providing sufficient intensity-gradient force. This condition results in a limited small trapping range to guarantee stable trapping of the particle. Exploiting structured light, i.e., an optical vortex beam, the trapping range can be enlarged by adjusting its doughnut ring diameter. However, the trapped particle scarcely remains static due to the optical spanner action of the orbital angular momentum of the vortex beam. To enlarge the trapping range and simultaneously ensure stable trapping, we propose a beam, referred to as a mirror-symmetric optical vortex beam (MOV). Essentially, MOV is constructed by using two opposite optical spanners and a pair of static optical tweezers. The optical spanners attract the particle to the site of the static optical tweezers, which realizes long-range optical trapping. Through detailed force-field analysis, it is found that MOV could perform these setting functions. In experiments, yeast cells are manipulated in a long range of similar to 25 mu m, which is 3 times longer than that of the Gaussian beam. Further, the trapping range is easily adjusted by changing a parameter as desired. This technique provides versatile optical tweezers, which will facilitate potential applications for particle manipulation. Published under license by AIP Publishing.
入藏号: WOS:000460134000008
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xinzhong         P-7966-2018         0000-0002-6426-4043
Zhang, Hao                  0000-0001-6514-9090
Ma, Haixiang                  0000-0001-9422-9372

ISSN: 0003-6951
eISSN: 1077-3118
________________________________________
第 264 条,共 344 条
标题: 3G structure for image caption generation
作者: Yuan, AH (Yuan, Aihong); Li, XL (Li, Xuelong); Lu, XQ (Lu, Xiaoqiang)
来源出版物: NEUROCOMPUTING 卷: 330 页: 17-28 DOI: 10.1016/j.neucom.2018.10.059 出版年: FEB 22 2019
摘要: It is a big challenge of computer vision to make machine automatically describe the content of an image with a natural language sentence. Previous works have made great progress on this task, but they only use the global or local image feature, which may lose some important subtle or global information of an image. In this paper, we propose a model with 3-gated model which fuses the global and local image features together for the task of image caption generation. The model mainly has three gated structures. (1) Gate for the global image feature, which can adaptively decide when and how much the global image feature should be imported into the sentence generator. (2) The gated recurrent neural network (RNN) is used as the sentence generator. (3) The gated feedback method for stacking RNN is employed to increase the capability of nonlinearity fitting. More specially, the global and local image features are combined together in this paper, which makes full use of the image information. The global image feature is controlled by the first gate and the local image feature is selected by the attention mechanism. With the latter two gates, the relationship between image and text can be well explored, which improves the performance of the language part as well as the multi-modal embedding part. Experimental results show that our proposed method outperforms the state-of-the-art for image caption generation. (C) 2018 Elsevier B.V. All rights reserved.
入藏号: WOS:000454789500003
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0925-2312
eISSN: 1872-8286
________________________________________
第 265 条,共 344 条
标题: Detection Analysis of Epileptic EEG Using a Novel Random Forest Mode Combined With Grid Search Optimization
作者: Wang, XS (Wang, Xiashuang); Gong, GH (Gong, Guanghong); Li, N (Li, Ni); Qiu, S (Qiu, Shi)
来源出版物: FRONTIERS IN HUMAN NEUROSCIENCE 卷: 13 文献号: 52 DOI: 10.3389/fnhum.2019.00052 出版年: FEB 21 2019
摘要: In the automatic detection of epileptic seizures, the monitoring of critically ill patients with time varying EEG signals is an essential procedure in intensive care units. There is an increasing interest in using EEG analysis to detect seizure, and in this study we aim to get a better understanding of how to visualize the information in the EEG time-frequency feature, and design and train a novel random forest algorithm for EEG decoding, especially for multiple-levels of illness. Here, we propose an automatic detection framework for epileptic seizure based on multiple time-frequency analysis approaches; it involves a novel random forest model combined with grid search optimization. The short-time Fourier transformation visualizes seizure features after normalization. The dimensionality of features is reduced through principal component analysis before feeding them into the classification model. The training parameters are optimized using grid search optimization to improve detection performance and diagnostic accuracy by in the recognition of three different levels epileptic of conditions (healthy subjects, seizure-free intervals, seizure activity). Our proposed model was used to classify 500 samples of raw EEG data, and multiple cross-validations were adopted to boost the modeling accuracy. Experimental results were evaluated by an accuracy, a confusion matrix, a receiver operating characteristic curve, and an area under the curve. The evaluations indicated that our model achieved the more effective classification than some previous typical methods. Such a scheme for computer-assisted clinical diagnosis of seizures has a potential guiding significance, which not only relieves the suffering of patient with epilepsy to improve quality of life, but also helps neurologists reduce their workload.
入藏号: WOS:000459301200002
PubMed ID: 30846934
ISSN: 1662-5161
________________________________________
第 266 条,共 344 条
标题: X-ray transmission characteristics and potential communication application in plasma region
作者: Li, Y (Li Yao); Su, T (Su Tong); Lei, F (Lei Fan); Xu, N (Xu Neng); Sheng, LZ (Sheng Li-Zhi); Zhao, BS (Zhao Bao-Sheng)
来源出版物: ACTA PHYSICA SINICA 卷: 68 期: 4 文献号: 040401 DOI: 10.7498/aps.68.20181973 出版年: FEB 20 2019
摘要: When a supersonic spacecraft enters into the atmosphere of earth, part of the spacecraft's kinetic energy changes into thermal energy, thus causing the air surrounding the craft to be heated and compressed. As a result, the temperature near the surface may reach several thousands of kelvins, which leads the surface materials to be ionized and form a plasma sheath around the vehicle. This plasma layer has an electron density ranging from 10(15)m(-3) to 10(20)m(-3), and may interrupt the radio communication signal between the re-entry vehicle and ground-based stations, which is known as `communication blackout'. According to the radio attenuation measurement (RAM) experiments carried out by NASA(National Aeronautics and Space Administration) in the 1970s, the duration time of communication blackout ranges from 4 to 10 minutes in an altitude range from 40 km to 100 km. Communication blackout has puzzled aerospace industry for several decades, and has not yet been completely resolved. Due to this, it becomes necessary to understand the causes of communication blackout and the methods for its mitigation. Compared with other communication methods, x-ray communication(XCOM) has the advantages of short carrier wavelength and high photon energy, as well as strong ability to resist anti-interference, thus being able to open a novel way to solve this long-lasting unresolved problem. In this paper, to begin with, we analyze the transmission coefficiencies under different plasma electron densities and collision frequencies based on Wentzel Kramers Brillouin (WKB) approximation method. The simulation results indicate that the x-ray carrier is not influenced by the reentry plasma sheath.
After that, a plasma source based on glow discharge is used to verify the mathematical model. The non-magnetized unobstructed plasma region is Phi 200 mm x 180 mm, which can be used for simulating plasma sheath near the reenter spacecraft. Then the transmission coefficiency, energy spectrum similarity and energy spectrum peak offset under different x-ray energy, x-ray flow and plasma electron density are firstly analyzed. Experimental results indicate that plasma can lead the x-ray signal to be attenuated to a certain extent, the increase of plasma electron density will cause higher attenuation. However, with a higher signal x-ray energy and x-ray flow, the XCOM could achieve less attenuation in the re-enter plasma layer. When the plasma electron density ranges from 6 x 10(16)/m(3) to 1.2 x 10(17)/m(3), 1.34 Mcps signal x-ray photons' flow with 20 kV anode voltage would achieve more than a 95% transmission efficiency. Also, the spectrum of x-ray signal can obtain more than 95.5% similarity and the peak offset is less than 1.3% after passing the plasma sheath. Subsequently, based on the original mathematic model and experimental results, considering the free-free absorption, free-bound absorption, bound-bound absorption and scattering effect of x-ray photons in plasma, the x-ray transmission characteristics are optimized to make simulation results well consistent with the experiment results. Finally, an MCNP (Monte Carlo N Particle) transport simulation is used to analyze the feasibility of XCOM in blackout region, which indicates that the energy range 15 25 keV is the suitable to achieve the XCOM in adjacent space, and the relation of potential transmitting speed with bit error is calculated. Theoretically, the XCOM can achieve about 1.3 Mbps communication speed in blackout region. In summary, these theoretical and experimental results indicate that the XCOM is a potential and novel method to solve the blackout communication problems.
入藏号: WOS:000460121500008
ISSN: 1000-3290
________________________________________
第 267 条,共 344 条
标题: Robust and flexible method for calibrating the focal length of on-orbit space zoom camera
作者: Zhang, GP (Zhang, Gaopeng); Zhao, H (Zhao, Hong); Yang, HT (Yang, Hongtao); Hong, Y (Hong, Yang); Ma, YY (Ma, Yueyang); Gu, FF (Gu, Feifei)
来源出版物: APPLIED OPTICS 卷: 58 期: 6 页: 1467-1474 DOI: 10.1364/AO.58.001467 出版年: FEB 20 2019
摘要: For the on-orbit space zoom camera, the camera focal length s in a constant process of change; accordingly, compared with calibrating other camera intrinsic parameters, calibrating the focal length has a practical significance for the space zoom camera. With the vanishing points obtained from the solar panel of human-made space satellites, this paper introduces a focal length self-calibration method for the on-orbit space zoom camera. First, the geometrical relationship and infinite homography of vanishing points at various camera positions are used to derive the method. To improve the accuracy and robustness performance of this approach, an optimization method is then proposed to nonlinearly optimize the camera focal length. Finally, simulation and real physical experiments demonstrate that the proposed method is flexible and accurate with good anti-noise interference and real-time capacity. The method proposed in this paper makes more realistic sense for a number of important space tasks. (C) 2019 Optical Society of America
入藏号: WOS:000459137900023
PubMed ID: 30874039
ISSN: 1559-128X
eISSN: 2155-3165
________________________________________
第 268 条,共 344 条
标题: Unveiling electrically tunable characteristics of second-order dispersion in graphene-silicon nitride waveguides
作者: Xie, P (Xie, Peng); Xue, MT (Xue, Mantian); Wen, Y (Wen, Yu); Li, XF (Li, Xiaofeng); Wang, XY (Wang, Xinyu); Yin, HY (Yin, Haoyi); Duo, CZ (Duo, Chengze); Liu, JR (Liu, Jiarui); Liu, JH (Liu, Jianhua)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 5 文献号: 1950053 DOI: 10.1142/S0217984919500532 出版年: FEB 20 2019
摘要: In this paper, we proposed a graphene-silicon nitride (GSN) waveguide model, which was unveiled to unveil its second-order dispersion (SOD) characteristics. The influences of the different thicknesses of graphene layer and the different heights from graphene to the core material of silicon nitride on SOD were investigated in detail. The tunability of SOD via controlling the bias voltage applied to the graphene layer was demonstrated and a 50 nm wavelength tuning was achieved with a small perturbation in voltage while keeping the geometric structure of the waveguide unchanged. Moreover, a flat SOD curve of the GSN waveguide was obtained with a large bandwidth of 700 nm between the two zero-dispersion wavelengths (ZDWs). These results provided significant insights for potential applications of graphene-related optoelectronic devices, integrated optics, and optical communications.
入藏号: WOS:000459457800011
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 269 条,共 344 条
标题: Large-scale 3D imaging of insects with natural color
作者: Qian, J (Qian, Jia); Dang, SP (Dang, Shipei); Wang, ZJ (Wang, Zhaojun); Zhou, X (Zhou, Xing); Dan, D (Dan, Dan); Yao, BL (Yao, Baoli); Tong, YJ (Tong, Yijie); Yang, HD (Yang, Haidong); Lu, YY (Lu, Yuanyuan); Chen, YD (Chen, Yandong); Yang, XK (Yang, Xingke); Bai, M (Bai, Ming); Lei, M (Lei, Ming)
来源出版物: OPTICS EXPRESS 卷: 27 期: 4 页: 4845-4857 DOI: 10.1364/OE.27.004845 出版年: FEB 18 2019
摘要: High-resolution 3D imaging technology has found a number of applications in many biological fields. However, the existing 3D imaging tools are often too time-consuming to use on large-scale specimens, such as centimeter-sized insects. In addition, most 3D imaging systems discard the natural color information of the specimens. To surmount these limitations, we present a structured illumination-based approach capable of delivering large field-of-view three-dimensional images. With this approach, 580nm lateral resolution full-color 3D images and 3D morphological data in the size range of typical insect samples can be obtained. This method provides a promising approach that can be used to support many different types of entomological investigations, including taxonomy, evolution, bionics, developmental biology, functional morphology, paleontology, forestry, etc. (C)2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000459152800100
PubMed ID: 30876094
ISSN: 1094-4087
________________________________________
第 270 条,共 344 条
标题: Real-time optical manipulation of particles through turbid media
作者: Peng, T (Peng, Tong); Li, RZ (Li, Runze); An, S (An, Sha); Yu, XH (Yu, Xianghua); Zhou, ML (Zhou, Meiling); Bai, C (Bai, Chen); Liang, YS (Liang, Yansheng); Lei, M (Lei, Ming); Zhang, CM (Zhang, Chunmin); Yao, BL (Yao, Baoli); Zhang, P (Zhang, Peng)
来源出版物: OPTICS EXPRESS 卷: 27 期: 4 页: 4858-4866 DOI: 10.1364/OE.27.004858 出版年: FEB 18 2019
摘要: Complex diffusive scattering media pose significant challenges for light focusing as well as optical imaging to be implemented in practice. Recently, it has been demonstrated that the wavefront shaping technique can be applied to realize focusing and imaging through scattering medium. Here we report dynamic optical manipulation of particles through turbid media by employing the interleaved segment wavefront correction method, which is an improved genetic algorithm providing faster convergence speed and higher peak to background ratio. Manipulating micro-beads behind a scattering medium along both one and two dimensional predesigned trajectories in real time has been successfully demonstrated. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000459152800101
PubMed ID: 30876095
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Peng, Tong                  0000-0003-0373-5136
Yu, Xianghua                  0000-0002-7447-1396

ISSN: 1094-4087
________________________________________
第 271 条,共 344 条
标题: Method of encapsulating silver nanodots using porous glass and its application in Q-switched a solid-state laser
作者: Zhang, GD (Zhang, Guodong); Li, GY (Li, Guangying); Zhang, YJ (Zhang, Yunjie); Wang, X (Wang, Xu); Cheng, GH (Cheng, Guanghua)
来源出版物: OPTICS EXPRESS 卷: 27 期: 4 页: 5337-5345 DOI: 10.1364/OE.27.005337 出版年: FEB 18 2019
摘要: Here, we report on a packaging method for silver nanodots (SNDs) by using high-silicate porous glass. Millions of nanopores, which arc randomly distributed in porous glass, are used as cells for SND nucleation and growth during the initial chemical-reduction process. Then, the sample is annealed at a high-temperature in a reducing atmosphere to impel the further SND growth and nanopore collapse. The compact SND-embedded transparent glass is synthesized in the end. Morphology characterization shows that the SNDs that are encapsulated in the sample have a uniform size of 1.5 to 4.5 nm. Both the sample's saturable and reverse saturable absorptions are observed under the irradiation of 100 fs laser pulses at 800 nm. Saturable absorption's threshhold is characterized to be 1.4 x 10(11) W/cm(2 ), which is much lower than what was ever reported. Furthermore, the SNDs-embedded silica as a saturable absorber (SA) has been demonstrated in the Q-switched Nd:YVO4 laser. The pulse duration as short as 53 nanoseconds is obtained. To our knowledge, it is the first time that SNDs are used as a SA in the passively Q-switched all solid-state laser. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000459152800139
PubMed ID: 30876133
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhang, Guodong                  0000-0001-9466-8105

ISSN: 1094-4087
________________________________________
第 272 条,共 344 条
标题: Three-dimensional space optimization for near-field ptychography
作者: Pan, A (Pan, An); Yao, BL (Yao, Baoli)
来源出版物: OPTICS EXPRESS 卷: 27 期: 4 页: 5433-5446 DOI: 10.1364/OE.27.005433 出版年: FEB 18 2019
摘要: A multiple slices approach in ptychography, termed 3ePIE algorithm, solves the multiple scattering problems of thick samples, which is crucial to biomedical imaging and in situ studies. However, it is unclear how many slices need to be separated and what the distance is between each layer respectively, while these two parameters are sensitive and crucial to the recovery of thick samples. The traditional method is to separate the sample with the same interval for convenience and to test the number of sections for the best reconstructions, which is reasonable for continuous samples and has achieved great results. But this kind of segmentation approach may not be scientific enough for those discrete samples with an uneven spatial distribution. The two inaccurate parameters may yield the algorithm to diverge or generate artifacts, and the empty slices may decrease the reconstruction quality and increase computation time. In addition, repeatedly testing the number of slices is tedious work even for a continuous sample. To this end, a genetic algorithm-based 3ePIE approach, termed the GA-3ePIE method, is proposed to retrieve both the interval between each layer and the number of slices. The performance is verified by both simulations and experiments. The maximum number of sections that can be resolved is also investigated in numerical analysis, which is associated with the sampling and overlap rate in a spatial domain. Our method can be also promoted to image thick samples with coherent X-rays and in the electron regime. The limitations of our method are also discussed. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000459152800148
PubMed ID: 30876147
ISSN: 1094-4087
________________________________________
第 273 条,共 344 条
标题: Advanced Adaptive Photonic RF Filters with 80 Taps Based on an Integrated Optical Micro-Comb Source
作者: Xu, XY (Xu, Xingyuan); Tan, MX (Tan, Mengxi); Wu, JY (Wu, Jiayang); Nguyen, TG (Nguyen, Thach G.); Chu, ST (Chu, Sai Tak); Little, BE (Little, Brent E.); Morandotti, R (Morandotti, Roberto); Mitchell, A (Mitchell, Arnan); Moss, DJ (Moss, David J.)
来源出版物: JOURNAL OF LIGHTWAVE TECHNOLOGY 卷: 37 期: 4 页: 1288-1295 DOI: 10.1109/JLT.2019.2892158 出版年: FEB 15 2019
摘要: We demonstrate a photonic radio frequency (RF) transversal filter based on an integrated optical micro-comb source featuring a record low free spectral range of 49 GHz, yielding 80 micro-comb lines across the C-band. This record high number of taps, or wavelengths for the transversal filter results in significantly increased performance including a Q(RF) factor more than four times higher than previous results. Furthermore, by employing both positive and negative taps, an improved out-of-band rejection of up to 48.9 dB is demonstrated using a Gaussian apodization, together with a tunable center frequency covering the RF spectra range, with a widely tunable 3-dB bandwidth and versatile dynamically adjustable filter shapes. Our experimental results match well with theory, showing that our transversal filter is a competitive solution to implement advanced adaptive RF filters with broad operational bandwidth, high frequency selectivity, high reconfigurability, and potentially reduced cost and footprint. This approach is promising for applications in modern radar and communications systems.
入藏号: WOS:000460331700028
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
Mitchell, Arnan         C-5017-2008         0000-0002-2463-2956
Wu, Jiayang                  0000-0003-1115-610X
Nguyen, Thach                  0000-0002-8409-5638

ISSN: 0733-8724
eISSN: 1558-2213
________________________________________
第 274 条,共 344 条
标题: The application of active polarization imaging technology of the vehicle theodolite
作者: Xie, ML (Xie, Meilin); Ma, CW (Ma, Caiwen); Liu, K (Liu, Kai); Liu, P (Liu, Peng); Hao, W (Hao, Wei); Han, JF (Han, Junfeng); Huang, W (Huang, Wei); Lian, XZ (Lian, Xuezheng); Feng, XB (Feng, Xubin); Jing, F (Jing, Feng)
来源出版物: OPTICS COMMUNICATIONS 卷: 433 页: 74-80 DOI: 10.1016/j.optcom.2018.09.056 出版年: FEB 15 2019
摘要: The vehicle theodolite has been the trend of the optical shooting range survey. While tracking and imaging of the long-distance dim targets have not been solved perfectly in this field, so this paper presents one active polarization imaging technology to find a way to deal with it. Firstly, we put forward a new active polarization imaging system with the lighting mode of circularly polarized laser and receives the reflected light by the mode of range-gating technique; secondly, deduces the pulse laser beam pointing algorithm; thirdly, describes the extended Kalman filtering algorithm to compensate the delay in the process and the calculation of the polarization angle, the attitude angle of flight target using single station cosine method and the depolarization of the circularly polarized laser. Finally, the result of this active polarization imaging technology which is simulated and analyzed in Simulink shows that the pointing precision can reach 0.0075 degrees. Then the analysis in this paper provide a theoretical basis for the application of the active polarization imaging technology in the field of the optical shooting range survey.
入藏号: WOS:000451337700012
ISSN: 0030-4018
eISSN: 1873-0310
________________________________________
第 275 条,共 344 条
标题: Sm3+-doped bismuthate glasses and proton-implanted near-infrared waveguides
作者: Chen, JY (Chen, Jing-Yi); Pan, H (Pan, He); Zhang, LL (Zhang, Liao-Lin); Guo, HT (Guo, Hai-Tao); Liu, CX (Liu, Chun-Xiao)
来源出版物: INTERNATIONAL JOURNAL OF MODERN PHYSICS B 卷: 33 期: 4 文献号: 1950004 DOI: 10.1142/S0217979219500048 出版年: FEB 10 2019
摘要: Sm3+-doped bismuthate glass has been synthesized by means of the classic melt-quenching technique. Its optical properties were characterized, which included refractive index, absorption and fluorescence spectra. The measured data suggest that the Sm3+-doped bismuthate glass is suitable for optoelectronic applications. A Sm3+-doped bismuthate glass waveguide operating at 1.539 mu m has been manufactured by using the proton implantation with a 0.4 MeV energy and a 8.0 x 10(16) ions.cm(-2) fluence for the first time to our knowledge. The effective refractive indices of the propagation modes for the glass waveguide were obtained by the m-line technique. The energy loss caused by the collision of the irradiated protons and the nuclei of the target Sm3+-doped bismuthate glass was calculated by the SRIM 2013. The refractive index profile and the near-field guided mode distribution for the waveguide structure were fitted through the reflectivity calculation method (RCM) and the FD-BPM method, respectively. The proton-implanted Sm3+-doped bismuthate glass waveguide is an alternative for an integrated device in the telecommunication band.
入藏号: WOS:000459292200005
ISSN: 0217-9792
eISSN: 1793-6578
________________________________________
第 276 条,共 344 条
标题: Target detection of hyperspectral image based on spectral saliency
作者: Zhang, XR (Zhang, Xiaorong); Pan, ZB (Pan, Zhibin); Hu, BL (Hu, Bingliang); Zheng, X (Zheng, Xi); Liu, WH (Liu, Weihua)
来源出版物: IET IMAGE PROCESSING 卷: 13 期: 2 页: 316-322 DOI: 10.1049/iet-ipr.2017.1173 出版年: FEB 7 2019
摘要: Target detection of hyperspectral image (HSI) is a research hotspot in the field of remote sensing. It is of particular importance in many domains, especially in military application. Unsupervised target detection is usually more difficult because there is no prior information about target. Traditional algorithms exploit spectral information, only. This study introduces the idea of saliency detection from the visual technique into HSI processing domain and proposes a novel approach named spectral saliency target detection (SSD). It establishes a novel salient model, which utilises both spatial saliency and spectral saliency. In the framework of SSD, it combines the model with spectral matching algorithm to make it perform well even in situations where the target is concealed and small. A HSI set comprised of eight different scenes with complex background is setup to evaluate the performance of the proposed algorithm. The final visible detection results demonstrate that the SSD algorithm outperforms the others. The receiver operation characteristic (ROC) curve and area under the ROC curve are applied to evaluate the results. The proposed algorithm shows superior and stable performance.
入藏号: WOS:000459477400011
ISSN: 1751-9659
eISSN: 1751-9667
________________________________________
第 277 条,共 344 条
标题: Endmember extraction from hyperspectral imagery based on QR factorisation using givens rotations
作者: Gan, YQ (Gan, Yuquan); Hu, BL (Hu, Bingliang); Liu, WH (Liu, Weihua); Wang, S (Wang, Shuang); Zhang, G (Zhang, Geng); Feng, XP (Feng, Xiangpeng); Wen, DS (Wen, Desheng)
来源出版物: IET IMAGE PROCESSING 卷: 13 期: 2 页: 332-343 DOI: 10.1049/iet-ipr.2018.5079 出版年: FEB 7 2019
摘要: Hyperspectral images are mixtures of spectra of materials in a scene. Accurate analysis of hyperspectral image requires spectral unmixing. The result of spectral unmixing is the material spectral signatures and their corresponding fractions. The materials are called endmembers. Endmember extraction equals to acquire spectral signatures of the materials. In this study, the authors propose a new hyperspectral endmember extraction algorithm for hyperspectral image based on QR factorisation using Givens rotations (EEGR). Evaluation of the algorithm is demonstrated by comparing its performance with two popular endmember extraction methods, which are vertex component analysis (VCA) and maximum volume by householder transformation (MVHT). Both simulated mixtures and real hyperspectral image are applied to the three algorithms, and the quantitative analysis of them is presented. EEGR exhibits better performance than VCA and MVHT. Moreover, EEGR algorithm is convenient to implement parallel computing for real-time applications based on the hardware features of Givens rotations.
入藏号: WOS:000459477400013
ISSN: 1751-9659
eISSN: 1751-9667
________________________________________
第 278 条,共 344 条
标题: Bidirectional adaptive feature fusion for remote sensing scene classification
作者: Lu, XQ (Lu, Xiaoqiang); Ji, WJ (Ji, Weijun); Li, XL (Li, Xuelong); Zheng, XT (Zheng, Xiangtao)
来源出版物: NEUROCOMPUTING 卷: 328 特刊: SI 页: 135-146 DOI: 10.1016/j.neucom.2018.03.076 出版年: FEB 7 2019
摘要: Scene classification has become an effective way to interpret the High Spatial Resolution (HSR) remote sensing images. Recently, Convolutional Neural Networks (CNN) have been found to be excellent for scene classification. However, only using the deep models as feature extractor on the aerial image directly is not proper, because the extracted deep features can not capture spatial scale variability and rotation variability in HSR remote sensing images. To relieve this limitation, a bidirectional adaptive feature fusion strategy is investigated to deal with the remote sensing scene classification. The deep learning feature and the SIFT feature are fused together to get a discriminative image presentation. The fused feature can not only describe the scenes effectively by employing deep learning feature but also overcome the scale and rotation variability with the usage of the SIFT feature. By fusing both SIFT feature and global CNN feature, our method achieves state-of-the-art scene classification performances on the UCMerced, the Sydney and the AID datasets. (C) 2018 Elsevier B.V. All rights reserved.
入藏号: WOS:000458065600015
会议名称: 2nd CCF Chinese Conference on Computer Vision (CCCV)
会议日期: OCT 11-14, 2017
会议地点: China Comp Federat, Tianjin, PEOPLES R CHINA
会议赞助商: China Comp Federat, Profess Comm Comp Vis, Civil Aviat Univ, Tianjin Univ, Nankai Univ, CCF Tech Comm Comp Vis, Megvii Face++, Sensetime, Isecure Technol, Ali A I Labs, Hiscene, Riseye, Tupu, Nvidia, Pingan Technol, Pinnacle, Vrview, Xilinx, Athena Eyes, Watrix Technol, Extreme Vis, Shanghai Acad Artificial Intelligence, Segway Robot, Percipio XYZ, AN
会议主办方: China Comp Federat
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Lu, Xiaoqiang                  0000-0002-7037-5188

ISSN: 0925-2312
eISSN: 1872-8286
________________________________________
第 279 条,共 344 条
标题: High energy closed-loop cycle narrow linewidth optically pumped XeF(C-A) blue laser at a repetition rate of 10 Hz
作者: Shen, YL (Shen, Yanlong); Zhu, F (Zhu, Feng); Yu, L (Yu, Li); Luan, KP (Luan, Kunpeng); Tao, MM (Tao, Mengmeng); Huang, C (Huang, Chao); Chen, HW (Chen, Hongwei); Ma, LY (Ma, Lianying); Zhao, L (Zhao, Liu); An, XX (An, Xiaoxia); Yi, AP (Yi, Aiping); Li, GP (Li, Gaopeng)
来源出版物: OPTICS EXPRESS 卷: 27 期: 3 页: 2258-2267 DOI: 10.1364/OE.27.002258 出版年: FEB 4 2019
摘要: We report for the first time on a closed-loop cycle narrow linewidth XeF(C-A) blue laser at a repetition rate of up to 10 Hz with each pulse energy of >1 J. A FWHM linewidth of less than 1.5 nm (minimum to 1.1 nm) with a highly stable wavelength centered at 488.3 nm was achieved by employing a polarization-independent custom-designed narrowband optical filter (NBOF) into the cavity. The pulse energy, as well as the repetition rate, to the best of our knowledge. is the highest ever reported in the narrow linewidth XeF(CA) blue lasers at repetitively-pulsed mode. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000457585600042
PubMed ID: 30732265
ISSN: 1094-4087
________________________________________
第 280 条,共 344 条
标题: Intelligent Evaluation of Strabismus in Videos Based on an Automated Cover Test
作者: Zheng, Y (Zheng, Yang); Fu, H (Fu, Hong); Li, RM (Li, Ruimin); Lo, WL (Lo, Wai-Lun); Chi, ZR (Chi, Zheru); Feng, DD (Feng, David Dagan); Song, ZX (Song, Zongxi); Wen, DS (Wen, Desheng)
来源出版物: APPLIED SCIENCES-BASEL 卷: 9 期: 4 文献号: 731 DOI: 10.3390/app9040731 出版年: FEB 2 2019
摘要: Strabismus is a common vision disease that brings about unpleasant influence on vision, as well as life quality. A timely diagnosis is crucial for the proper treatment of strabismus. In contrast to manual evaluation, well-designed automatic evaluation can significantly improve the objectivity, reliability, and efficiency of strabismus diagnosis. In this study, we have proposed an innovative intelligent evaluation system of strabismus in digital videos, based on the cover test. In particular, the video is recorded using an infrared camera, while the subject performs automated cover tests. The video is then fed into the proposed algorithm that consists of six stages: (1) eye region extraction, (2) iris boundary detection, (3) key frame detection, (4) pupil localization, (5) deviation calculation, and (6) evaluation of strabismus. A database containing cover test data of both strabismic subjects and normal subjects was established for experiments. Experimental results demonstrate that the deviation of strabismus can be well-evaluated by our proposed method. The accuracy was over 91%, in the horizontal direction, with an error of 8 diopters; and it was over 86% in the vertical direction, with an error of 4 diopters.
入藏号: WOS:000460696500117
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
fu, hong                  0000-0003-2246-7552

ISSN: 2076-3417
________________________________________
第 281 条,共 344 条
标题: Fast Spectral Clustering for Unsupervised Hyperspectral Image Classification
作者: Zhao, Y (Zhao, Yang); Yuan, Y (Yuan, Yuan); Wang, Q (Wang, Qi)
来源出版物: REMOTE SENSING 卷: 11 期: 4 文献号: 399 DOI: 10.3390/rs11040399 出版年: FEB 2 2019
摘要: Hyperspectral image classification is a challenging and significant domain in the field of remote sensing with numerous applications in agriculture, environmental science, mineralogy, and surveillance. In the past years, a growing number of advanced hyperspectral remote sensing image classification techniques based on manifold learning, sparse representation and deep learning have been proposed and reported a good performance in accuracy and efficiency on state-of-the-art public datasets. However, most existing methods still face challenges in dealing with large-scale hyperspectral image datasets due to their high computational complexity. In this work, we propose an improved spectral clustering method for large-scale hyperspectral image classification without any prior information. The proposed algorithm introduces two efficient approximation techniques based on Nystrom extension and anchor-based graph to construct the affinity matrix. We also propose an effective solution to solve the eigenvalue decomposition problem by multiplicative update optimization. Experiments on both the synthetic datasets and the hyperspectral image datasets were conducted to demonstrate the efficiency and effectiveness of the proposed algorithm.
入藏号: WOS:000460766100029
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Qi                  0000-0002-7028-4956

ISSN: 2072-4292
________________________________________
第 282 条,共 344 条
标题: An optical design for dual-band infrared diffractive telescope
作者: Wang, H (Wang Hao); Kang, FZ (Kang Fu-Zeng); Zhao, W (Zhao Wei); Li, YC (Li Yi-Chao)
来源出版物: JOURNAL OF INFRARED AND MILLIMETER WAVES 卷: 38 期: 1 页: 39-43 DOI: 10.11972/j.issn.1001-9014.2019.01.007 出版年: FEB 2019
摘要: In this paper, the double-layer harmonic diffractive element (HDE) structure is investigated and the optimization procedure is based on the equation of diffraction efficiency of the double-layer diffractive optical element. The diffraction efficiency of the system in the designed middle and far infrared wavebands is larger than 99%, which improves the image contrast and the imagequality significantly. A new dual-band infrared double-layer HDE telescope is designed, which can work in the middle and far infrared wavebands. It is shown that the system approximately attains diffraction limit and is easy to processed.
入藏号: WOS:000460879300007
ISSN: 1001-9014
________________________________________
第 283 条,共 344 条
标题: Deterministic generation and switching of dissipative Kerr soliton in a thermally controlled micro-resonator
作者: Lu, ZZ (Lu, Zhizhou); Wang, WQ (Wang, Weiqiang); Zhang, WF (Zhang, Wenfu); Chu, ST (Chu, Sai T.); Little, BE (Little, Brent E.); Liu, ML (Liu, Mulong); Wang, LR (Wang, Leiran); Zou, CL (Zou, Chang-Ling); Dong, CH (Dong, Chun-Hua); Zhao, BL (Zhao, Bailing); Zhao, W (Zhao, Wei)
来源出版物: AIP ADVANCES 卷: 9 期: 2 文献号: 025314 DOI: 10.1063/1.5080128 出版年: FEB 2019
摘要: In this paper, we first experimentally demonstrate deterministic generation and switching of dissipative Kerr solitons (DKSs) in a thermally controlled micro-ring resonator based on high-index doped silica glass platform. In our scheme, an auxiliary laser is introduced to timely balance the intra-cavity heat fluctuation. By decreasing the operation temperature through a thermo-electric cooler, primary-, chaotic-comb and soliton crystal are firstly generated, then increasing the temperature, DKSs switching and single soliton are robustly accessed, which is independent of the tuning speed. During the switching process, varieties of DKSs are identified by tens of the characteristic "soliton-steps". Besides, by simply changing the operation temperature under which the DKSs are formed, the center wavelength of dispersive waves could be tuned in a broadband range. When the micro-ring resonator operating at temperature larger than 63.5 degrees C, avoided mode-crossing free soliton can be obtained. Our results are favorable for study of on-chip soliton dynamics and practical nonlinear applications. (c) 2019 Author(s).
入藏号: WOS:000460029500102
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zou, Chang-Ling         G-1536-2010         0000-0003-2484-7292
Chu, Sai T         D-3312-2014         0000-0001-8263-8507

ISSN: 2158-3226
________________________________________
第 284 条,共 344 条
标题: Femtosecond Laser Irradiation of Carbon Nanotubes to Metal Electrodes
作者: Cui, JL (Cui, Jianlei); Cheng, Y (Cheng, Yang); Zhang, JW (Zhang, Jianwei); Mei, HH (Mei, Huanhuan); Wang, XW (Wang, Xuewen)
来源出版物: APPLIED SCIENCES-BASEL 卷: 9 期: 3 文献号: 476 DOI: 10.3390/app9030476 出版年: FEB 1 2019
摘要: Carbon nanotubes (CNTs) have excellent performance, which means that they could be better electrical conductors. However, the problem of the connection of CNTs to electrodes limits their application. Particularly, improving connection efficiency while ensuring the quality of the connection is a big challenge, because it is difficult to form Ohmic contact between CNTs and electrodes. To address this issue, we propose the use of a femtosecond laser to irradiate the contact surface between the CNTs and the electrodes to obtain a good connection quality and electrical performance. At the same time, since the laser-induced connection acts on all the contact surfaces in the irradiation area, the connection efficiency can be improved, which provides a new idea for the large-scale preparation of the connection.
入藏号: WOS:000459976200116
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Cui, Jianlei                  0000-0002-5760-509X

ISSN: 2076-3417
________________________________________
第 285 条,共 344 条
标题: The Spectral-Spatial Joint Learning for Change Detection in Multispectral Imagery
作者: Zhang, WX (Zhang, Wuxia); Lu, XQ (Lu, Xiaoqiang)
来源出版物: REMOTE SENSING 卷: 11 期: 3 文献号: 240 DOI: 10.3390/rs11030240 出版年: FEB 1 2019
摘要: Change detection is one of the most important applications in the remote sensing domain. More and more attention is focused on deep neural network based change detection methods. However, many deep neural networks based methods did not take both the spectral and spatial information into account. Moreover, the underlying information of fused features is not fully explored. To address the above-mentioned problems, a Spectral-Spatial Joint Learning Network (SSJLN) is proposed. SSJLN contains three parts: spectral-spatial joint representation, feature fusion, and discrimination learning. First, the spectral-spatial joint representation is extracted from the network similar to the Siamese CNN (S-CNN). Second, the above-extracted features are fused to represent the difference information that proves to be effective for the change detection task. Third, the discrimination learning is presented to explore the underlying information of obtained fused features to better represent the discrimination. Moreover, we present a new loss function that considers both the losses of the spectral-spatial joint representation procedure and the discrimination learning procedure. The effectiveness of our proposed SSJLN is verified on four real data sets. Extensive experimental results show that our proposed SSJLN can outperform the other state-of-the-art change detection methods.
入藏号: WOS:000459944400028
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhang, Wuxia                  0000-0002-0759-2489

ISSN: 2072-4292
________________________________________
第 286 条,共 344 条
标题: Measurement Matrix Construction for Large-area Single Photon Compressive Imaging
作者: Wang, H (Wang, Hui); Yan, QR (Yan, Qiurong); Li, B (Li, Bing); Yuan, CL (Yuan, Chenglong); Wang, YH (Wang, Yuhao)
来源出版物: SENSORS 卷: 19 期: 3 文献号: 474 DOI: 10.3390/s19030474 出版年: FEB 1 2019
摘要: We have developed a single photon compressive imaging system based on single photon counting technology and compressed sensing theory, using a photomultiplier tube (PMT) photon counting head as the bucket detector. This system can realize ultra-weak light imaging with the imaging area up to the entire digital micromirror device (DMD) working region. The measurement matrix in this system is required to be binary due to the two working states of the micromirror corresponding to two controlled elements. And it has a great impact on the performance of the imaging system, because it involves modulation of the optical signal and image reconstruction. Three kinds of binary matrix including sparse binary random matrix, m sequence matrix and true random number matrix are constructed. The properties of these matrices are analyzed theoretically with the uncertainty principle. The parameters of measurement matrix including sparsity ratio, compressive sampling ratio and reconstruction time are verified in the experimental system. The experimental results show that, the increase of sparsity ratio and compressive sampling ratio can improve the reconstruction quality. However, when the increase is up to a certain value, the reconstruction quality tends to be saturated. Compared to the other two types of measurement matrices, the m sequence matrix has better performance in image reconstruction.
入藏号: WOS:000459941200037
PubMed ID: 30682792
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Yuhao         O-9322-2019         0000-0002-8445-0361
Yan, Qiurong                  0000-0003-4736-7435

ISSN: 1424-8220
________________________________________
第 287 条,共 344 条
标题: High performance RF filters via bandwidth scaling with Kerr micro-combs
作者: Xu, XY (Xu, Xingyuan); Tan, MX (Tan, Mengxi); Wu, JY (Wu, Jiayang); Nguyen, TG (Nguyen, Thach G.); Chu, ST (Chu, Sai T.); Little, BE (Little, Brent E.); Morandotti, R (Morandotti, Roberto); Mitchell, A (Mitchell, Arnan); Moss, DJ (Moss, David J.)
来源出版物: APL PHOTONICS 卷: 4 期: 2 文献号: 026102 DOI: 10.1063/1.5080246 出版年: FEB 2019
摘要: We demonstrate high-resolution photonic RF filters using an RF bandwidth scaling approach based on integrated Kerr optical micro-combs. By employing both an active nonlinear micro-ring resonator (MRR) as a high-quality micro-comb source and a passive high-Q MRR to slice the RF spectra modulated on the shaped comb, a large RF instantaneous bandwidth of 4.64 GHz and a high resolution of 117 MHz are achieved, together with a broad RF operation band covering 3.28-19.4 GHz (L to Ku bands) using thermal tuning. We achieve programmable RF transfer functions including binary-coded notch filters and RF equalizing filters with reconfigurable slopes. Our approach is an attractive solution for RF spectral shaping with high performance and flexibility. (C) 2019 Author(s).
入藏号: WOS:000460031000018
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
Wu, Jiayang         Q-8590-2019         0000-0003-1115-610X
Nguyen, Thach                  0000-0002-8409-5638

ISSN: 2378-0967
________________________________________
第 288 条,共 344 条
标题: The enhanced X-ray Timing and Polarimetry mission-eXTP
作者: Zhang, SN (Zhang, ShuangNan); Santangelo, A (Santangelo, Andrea); Feroci, M (Feroci, Marco); Xu, YP (Xu, YuPeng); Lu, FJ (Lu, FangJun); Chen, Y (Chen, Yong); Feng, H (Feng, Hua); Zhang, S (Zhang, Shu); Brandt, S (Brandt, Soren); Hernanz, M (Hernanz, Margarita); Baldini, L (Baldini, Luca); Bozzo, E (Bozzo, Enrico); Campana, R (Campana, Riccardo); De Rosa, A (De Rosa, Alessandra); Dong, YW (Dong, YongWei); Evangelista, Y (Evangelista, Yuri); Karas, V (Karas, Vladimir); Meidinger, N (Meidinger, Norbert); Meuris, A (Meuris, Aline); Nandra, K (Nandra, Kirpal); Pan, T (Pan, Teng); Pareschi, G (Pareschi, Giovanni); Orleanski, P (Orleanski, Piotr); Huang, QS (Huang, QiuShi); Schanne, S (Schanne, Stephane); Sironi, G (Sironi, Giorgia); Spiga, D (Spiga, Daniele); Svoboda, J (Svoboda, Jiri); Tagliaferri, G (Tagliaferri, Gianpiero); Tenzer, C (Tenzer, Christoph); Vacchi, A (Vacchi, Andrea); Zane, S (Zane, Silvia); Walton, D (Walton, Dave); Wang, ZS (Wang, ZhanShan); Winter, B (Winter, Berend); Wu, X (Wu, Xin); In't Zand, JJM (In't Zand, Jean J. M.); Ahangarianabhari, M (Ahangarianabhari, Mahdi); Ambrosi, G (Ambrosi, Giovanni); Ambrosino, F (Ambrosino, Filippo); Barbera, M (Barbera, Marco); Basso, S (Basso, Stefano); Bayer, J (Bayer, Joerg); Bellazzini, R (Bellazzini, Ronaldo); Bellutti, P (Bellutti, Pierluigi); Bertucci, B (Bertucci, Bruna); Bertuccio, G (Bertuccio, Giuseppe); Borghi, G (Borghi, Giacomo); Cao, XL (Cao, XueLei); Cadoux, F (Cadoux, Franck); Campana, R (Campana, Riccardo); Ceraudo, F (Ceraudo, Francesco); Chen, TX (Chen, TianXiang); Chen, YP (Chen, YuPeng); Chevenez, J (Chevenez, Jerome); Civitani, M (Civitani, Marta); Cui, W (Cui, Wei); Cui, WW (Cui, WeiWei); Dauser, T (Dauser, Thomas); Del Monte, E (Del Monte, Ettore); Di Cosimo, S (Di Cosimo, Sergio); Diebold, S (Diebold, Sebastian); Doroshenko, V (Doroshenko, Victor); Dovciak, M (Dovciak, Michal); Du, YY (Du, YuanYuan); Ducci, L (Ducci, Lorenzo); Fan, QM (Fan, QingMei); Favre, Y (Favre, Yannick); Fuschino, F (Fuschino, Fabio); Galvez, JL (Luis Galvez, Jose); Gao, M (Gao, Min); Ge, MY (Ge, MingYu); Gevin, O (Gevin, Olivier); Grassi, M (Grassi, Marco); Gu, QY (Gu, QuanYing); Gu, YD (Gu, YuDong); Han, DW (Han, Dawei); Hong, B (Hong, Bin); Hu, W (Hu, Wei); Ji, L (Ji, Long); Jia, SM (Jia, ShuMei); Jiang, WC (Jiang, WeiChun); Kennedy, T (Kennedy, Thomas); Kreykenbohm, I (Kreykenbohm, Ingo); Kuvvetli, I (Kuvvetli, Irfan); Labanti, C (Labanti, Claudio); Latronico, L (Latronico, Luca); Li, G (Li, Gang); Li, MS (Li, MaoShun); Li, X (Li, Xian); Li, W (Li, Wei); Li, ZW (Li, ZhengWei); Limousin, O (Limousin, Olivier); Liu, HW (Liu, HongWei); Liu, XJ (Liu, XiaoJing); Lu, B (Lu, Bo); Luo, T (Luo, Tao); Macera, D (Macera, Daniele); Malcovati, P (Malcovati, Piero); Martindale, A (Martindale, Adrian); Michalska, M (Michalska, Malgorzata); Meng, B (Meng, Bin); Minuti, M (Minuti, Massimo); Morbidini, A (Morbidini, Alfredo); Muleri, F (Muleri, Fabio); Paltani, S (Paltani, Stephane); Perinati, E (Perinati, Emanuele); Picciotto, A (Picciotto, Antonino); Piemonte, C (Piemonte, Claudio); Qu, JL (Qu, JinLu); Rachevski, A (Rachevski, Alexandre); Rashevskaya, I (Rashevskaya, Irina); Rodriguez, J (Rodriguez, Jerome); Schanz, T (Schanz, Thomas); Shen, ZX (Shen, ZhengXiang); Sheng, LZ (Sheng, Lizhi); Song, JB (Song, JiangBo); Song, LM (Song, LiMing); Sgro, C (Sgro, Carmelo); Sun, L (Sun, Liang); Tan, Y (Tan, Ying); Uttley, P (Uttley, Phil); Wang, B (Wang, Bo); Wang, DL (Wang, DianLong); Wang, GF (Wang, GuoFeng); Wang, J (Wang, Juan); Wang, LP (Wang, LangPing); Wang, YS (Wang, YuSa); Watts, AL (Watts, Anna L.); Wen, XY (Wen, XiangYang); Wilms, J (Wilms, Joern); Xiong, SL (Xiong, ShaoLin); Yang, JW (Yang, JiaWei); Yang, S (Yang, Sheng); Yang, YJ (Yang, YanJi); Yu, N (Yu, Nian); Zhang, WD (Zhang, WenDa); Zampa, G (Zampa, Gianluigi); Zampa, N (Zampa, Nicola); Zdziarski, AA (Zdziarski, Andrzej A.); Zhang, AM (Zhang, AiMei); Zhang, CM (Zhang, ChengMo); Zhang, F (Zhang, Fan); Zhang, L (Zhang, Long); Zhang, T (Zhang, Tong); Zhang, Y (Zhang, Yi); Zhang, XL (Zhang, XiaoLi); Zhang, ZL (Zhang, ZiLiang); Zhao, BS (Zhao, BaoSheng); Zheng, SJ (Zheng, ShiJie); Zhou, YP (Zhou, YuPeng); Zorzi, N (Zorzi, Nicola); Zwart, JF (Zwart, J. Frans)
来源出版物: SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY 卷: 62 期: 2 特刊: SI 文献号: 029502 DOI: 10.1007/s11433-018-9309-2 出版年: FEB 2019
摘要: In this paper we present the enhanced X-ray Timing and Polarimetry mission-eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to detect the electro-magnetic counterparts of gravitational wave sources. The paper provides a detailed description of: (1) the technological and technical aspects, and the expected performance of the instruments of the scientific payload; (2) the elements and functions of the mission, from the spacecraft to the ground segment.
入藏号: WOS:000459907000001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Dovciak, Michal         M-2284-2019         0000-0003-0079-1239
Svoboda, Jiri         V-2690-2019         0000-0003-2931-0742
Zorzi, Nicola         M-3141-2014         0000-0002-6650-3925
Dovciak, Michal         F-4258-2014         0000-0003-0079-1239
Malcovati, Piero         S-2458-2016         0000-0001-6514-9672
Wilms, Joern         C-8116-2013         0000-0003-2065-5410
GALVEZ, JOSE-LUIS         B-6801-2017         0000-0003-4513-0573
Campana, Riccardo         F-5272-2015         0000-0002-4794-5453
De Rosa, Alessandra                  0000-0001-5668-6863
Sironi, Giorgia                  0000-0002-8102-7349
Brandt, Soren                  0000-0001-5689-3109
Civitani, Marta                  0000-0002-6650-1647
Labanti, Claudio                  0000-0002-5086-3619
Basso, Stefano                  0000-0002-2342-5090
Karas, Vladimir         C-1559-2013         0000-0002-5760-0459
Ducci, Lorenzo                  0000-0002-9989-538X
Zhang, Wenda                  0000-0003-1702-4917
Del Monte, Ettore                  0000-0002-3013-6334
Zane, Silvia                  0000-0001-5326-880X
Tagliaferri, Gianpiero                  0000-0003-0121-0723
Evangelista, Yuri                  0000-0001-6096-6710
BERTUCCIO, GIUSEPPE                  0000-0002-7283-021X
Pareschi, Giovanni                  0000-0003-3967-403X
Spiga, Daniele                  0000-0003-1163-7843
Muleri, Fabio                  0000-0003-3331-3794
Ambrosino, Filippo                  0000-0001-7915-996X
Baldini, Luca                  0000-0002-9785-7726
Vacchi, Andrea         C-1291-2010         0000-0003-3855-5856

ISSN: 1674-7348
eISSN: 1869-1927
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第 289 条,共 344 条
标题: Simultaneous polarization separation and switching for 100-Gbps DP-QPSK signals in backbone networks
作者: Su, YL (Su, Yu-Long); Feng, H (Feng, Huan); Hu, H (Hu, Hui); Wang, W (Wang, Wei); Duan, T (Duan, Tao); Wang, YS (Wang, Yi-Shan); Si, JH (Si, Jin-Hai); Xie, XP (Xie, Xiao-Ping); Yang, HN (Yang, He-Ning); Huang, XN (Huang, Xin-Ning)
来源出版物: CHINESE PHYSICS B 卷: 28 期: 2 文献号: 024216 DOI: 10.1088/1674-1056/28/2/024216 出版年: FEB 2019
摘要: We propose a novel scheme of simultaneous polarization separation and switching, based on the orthogonally-polarized four-wave mixing (FWM) effect, for ultra-high-speed polarization multiplexing (Pol-MUX) fiber networks such as 100-Gbps and 400-Gbps backbone networks. We use theoretical and experimental analysis of the vector theory of FWM to successfully achieve polarization separation and all-optical switching by utilizing a 100-Gbps dual polarization-quadrature phase shift keying (DP-QPSK) signal and two orthogonally-polarized pumps. Both of the polarization-separated QPSK signals have clear constellation diagrams, with root mean square (RMS) error vector magnitudes (EVMs) of 14.32% and 14.11% respectively. The wavelengths of idlers can be created at 30 different wavelengths, which are consistent with International Telecommunication Union-Telecommunication (ITU-T) wavelengths, by flexibly changing the wavelength of the pump light. Moreover, the idlers that have distinct wavelengths have power distributed in a range from 10 dBm to -15 dBm, which can support error-free transmission. The power penaltyis 5 dB lower than that of back-to-back (BTB) signal for both the X- and Y-polarization components measured at a bit error ratio (BER) of 3.8 x10(-3). Our experimental results indicate that this scheme has promising applications in future backbone networks.
入藏号: WOS:000458917000016
ISSN: 1674-1056
eISSN: 1741-4199
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第 290 条,共 344 条
标题: Robotic Arm Based Automatic Ultrasound Scanning for Three-Dimensional Imaging
作者: Huang, QH (Huang, Qinghua); Lan, JL (Lan, Jiulong); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS 卷: 15 期: 2 页: 1173-1182 DOI: 10.1109/TII.2018.2871864 出版年: FEB 2019
摘要: This paper presents a human skin inspired automatic robotic ultrasound (US) system for three-dimensional (3-D) imaging. A depth camera was adopted to capture the point cloud of the skin surface. According to the 3-D contour of the skin surface, the scan range and scan path for the US probe could be automatically determined. Then, we used a normal-vector-based method to determine the pose of the robotic arm corresponding to each scan point in the scan path. In addition, two force sensors could feedback the contact force between the scanned tissue and the emission plane of the probe for fine-tuning the pose of the robotic arm. After the scanning, the system could realize 3-D US reconstruction. Experimental results validate the feasibility of the proposed system. It is expected that the proposed system will be useful in clinical practices.
入藏号: WOS:000458199000053
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Huang, Qinghua         L-8708-2019         0000-0003-1080-6940

ISSN: 1551-3203
eISSN: 1941-0050
________________________________________
第 291 条,共 344 条
标题: Indium selenide as a saturable absorber for a wavelength-switchable vector-soliton fiber laser
作者: Wang, GM (Wang, Guomei); Chen, GW (Chen, Guangwei); Li, WL (Li, Wenlei); Zhang, WF (Zhang, Wenfu); Zeng, C (Zeng, Chao); Zhao, W (Zhao, Wei)
来源出版物: OPTICAL MATERIALS EXPRESS 卷: 9 期: 2 页: 449-456 DOI: 10.1364/OME.9.000449 出版年: FEB 1 2019
摘要: We experimentally demonstrate that indium selenide (In2Se3), a III-VI group layered chalcogenide compound. can be used as a saturable absorber (SA) for a wavelength-switchable vector-soliton fiber laser. The modulation depth of the In2Se3-based SA (In2Se3-SA), fabricated by incorporating In2Se3 nanosheets with polyvinyl alcohol, is up to 14%. By inserting the In2Se3-SA into fiber laser, solitons switched at wavelengths of similar to 1558 and similar to 1530 nm, with the duration of similar to 1.88 and similar to 1.76 ps respectively, can be obtained by adjusting the polarization controller and the pump power. Further investigations demonstrate that the achieved solitons arc polarization-locked vector conventional solitons, which reveals that the In2Se3 can serves as a polarization-independent SA. The results indicate that the III-VI group chalcogenide compounds, including In2Se3. could be developed as an alternative for ultrafast pulse generations, particularly, vector-soliton pulse. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
入藏号: WOS:000457500500011
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zeng, Chao                  0000-0003-0097-6399

ISSN: 2159-3930
________________________________________
第 292 条,共 344 条
标题: Influence of Layup Sequence on the Surface Accuracy of Carbon Fiber Composite Space Mirrors
作者: Yang, ZY (Yang, Zhiyong); Liu, QN (Liu, Qingnian); Zhang, BM (Zhang, Boming); Xu, L (Xu, Liang); Tang, ZW (Tang, Zhanwen); Xie, YJ (Xie, Yongjie)
来源出版物: APPLIED COMPOSITE MATERIALS 卷: 26 期: 1 页: 219-238 DOI: 10.1007/s10443-018-9690-4 出版年: FEB 2019
摘要: Layup sequence is directly related to stiffness and deformation resistance of the composite space mirror, and error caused by layup sequence can affect the surface precision of composite mirrors evidently. Variation of layup sequence with the same total thickness of composite space mirror changes surface form of the composite mirror, which is the focus of our study. In our research, the influence of varied quasi-isotropic stacking sequences and random angular deviation on the surface accuracy of composite space mirrors was investigated through finite element analyses (FEA). We established a simulation model for the studied concave mirror with 500mm diameter, essential factors of layup sequences and random angular deviations on different plies were discussed. Five guiding findings were described in this study. Increasing total plies, optimizing stacking sequence and keeping consistency of ply alignment in ply placement are effective to improve surface accuracy of composite mirror.
入藏号: WOS:000457245900012
ISSN: 0929-189X
eISSN: 1573-4897
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第 293 条,共 344 条
标题: Influence of Layup Sequence on the Surface Accuracy of Carbon Fiber Composite Space Mirrors (vol 26, pg 219, 2019)
作者: Yang, ZY (Yang, Zhiyong); Liu, QN (Liu, Qingnian); Zhang, BM (Zhang, Boming); Xu, L (Xu, Liang); Tang, ZW (Tang, Zhanwen); Xie, YJ (Xie, Yongjie)
来源出版物: APPLIED COMPOSITE MATERIALS 卷: 26 期: 1 页: 239-247 DOI: 10.1007/s10443-018-9740-y 出版年: FEB 2019
入藏号: WOS:000457245900013
ISSN: 0929-189X
eISSN: 1573-4897
________________________________________
第 294 条,共 344 条
标题: Simulation and observation for volume emission rates emitted from O-2(0-1) and O(S-1) nightglow in northwest China
作者: Tang, YH (Tang, Yuanhe); Sun, P (Sun, Peng); Gao, HY (Gao, Haiyang); Cui, J (Cui, Jin); Li, ZJ (Li, Zijian); Wang, HX (Wang, Haoxuan); Lv, H (Lv, Huan); Jia, M (Jia, Min); Liu, HC (Liu, Hanchen); Li, CX (Li, Cunxia); Liu, QS (Liu, Qingsong)
来源出版物: APPLIED OPTICS 卷: 58 期: 4 页: 1093-1100 DOI: 10.1364/AO.58.001093 出版年: FEB 1 2019
摘要: Being susceptible to the change of atmospheric conditions, the volume emission rate (VER) is very suitable to be used as a light source by passive remote sensing for measuring atmospheric wind and temperature. Thus, the VERs emitted from O-2(0-1) and O(S-1) of the nightglow at 80-120 km are studied in this paper. Based on the Naval Research Laboratory Mass Spectrometer Incoherent Scatter (NRLMSISE-00) model data and the ground-based airglow imaging interferometer (GBAII) instrument observation for a local time and place, simulated VER profiles represented by four layers are obtained for the nightglow of O-2(0-1) and O(S-1). The O-2(0-1) nightglow model peak values at 94 km on 6 December 2013 and 8 November 2011 are 8111 photons . cm (-3) . s (-1) and 8406 photons . cm (-3) . s (-1) , respectively; however, the O(S-1) VER peak at a higher altitude of about 96 km on 18 December 2011 is only 338 photons . cm (-3) . s (-1) . The upper atmospheric VER values have been derived to transfer into the ground-based detected column intensities by our GBAII prototype. The calculated column integrated emission rates (IERs) of O-2(0-1) for 0 degrees and 45 degrees zenith angles are 1.48 x 10(7) and 1.91 x 10(7) photons. cm (-2) . s (-1) , respectively; the calculated column IERs of O(S-1) are 5.53 x 10(5) and 7.03 x 10(5) photons. cm (-2) . s (-1) , respectively. Correspondingly, the detected column IERs obtained by GBAII are 2.43 x 10(7) for O-2(0-1) and 6.57 x 10(5) photons. cm (-2) . s (-1) for O(S-1). (C) 2019 Optical Society of America
入藏号: WOS:000457471400047
PubMed ID: 30874163
ISSN: 1559-128X
eISSN: 2155-3165
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第 295 条,共 344 条
标题: An on-chip photon-pair source with negligible two-photon absoprtion
作者: Sugiura, K (Sugiura, Kenta); Okamoto, R (Okamoto, Ryo); Zhang, LB (Zhang, Labao); Kang, L (Kang, Lin); Chen, J (Chen, Jian); Wu, PH (Wu, Peiheng); Chu, ST (Chu, Sai T.); Little, BE (Little, Brent E.); Takeuchi, S (Takeuchi, Shigeki)
来源出版物: APPLIED PHYSICS EXPRESS 卷: 12 期: 2 文献号: 022006 DOI: 10.7567/1882-0786/aafa0f 出版年: FEB 2019
摘要: While photon-pair sources using silicon waveguides have shown great promise, strong two-photon absorption (TPA) may limit their brightness. Recently, high-index contrast doped glass (HICDG) has attracted attention because of its CMOS compatibility and low propagation loss. It is also expected that TPA in HICDG is small, though it has not yet been directly measured by conventionally used CW pumping. In this paper, we report that the estimated genuine coincidence events by photon-pairs increase quadratically as the pump power increased and do not show any saturation behavior up to 100 mW CW pump power. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000456867100001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Chu, Sai T         D-3312-2014         0000-0001-8263-8507

ISSN: 1882-0778
eISSN: 1882-0786
________________________________________
第 296 条,共 344 条
标题: Locality and Structure Regularized Low Rank Representation for Hyperspectral Image Classification
作者: Wang, Q (Wang, Qi); He, X (He, Xiang); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 2 页: 911-923 DOI: 10.1109/TGRS.2018.2862899 出版年: FEB 2019
摘要: Hyperspectral image (HSI) classification, which aims to assign an accurate label for hyperspectral pixels, has drawn great interest in recent years. Although low-rank representation (LRR) has been used to classify HSI, its ability to segment each class from the whole HSI data has not been exploited fully yet. LRR has a good capacity to capture the underlying low-dimensional subspaces embedded in original data. However, there are still two drawbacks for LRR. First, the LRR does not consider the local geometric structure within data, which makes the local correlation among neighboring data easily ignored. Second, the representation obtained by solving LRR is not discriminative enough to separate different data. In this paper, a novel locality- and structure-regularized LRR (LSLRR) model is proposed for HSI classification. To overcome the above-mentioned limitations, we present locality constraint criterion and structure preserving strategy to improve the classical LRR. Specifically, we introduce a new distance metric, which combines both spatial and spectral features, to explore the local similarity of pixels. Thus, the global and local structures of HSI data can be exploited sufficiently. In addition, we propose a structural constraint to make the representation have a near-block-diagonal structure. This helps to determine the final classification labels directly. Extensive experiments have been conducted on three popular HSI data sets. And the experimental results demonstrate that the proposed LSLRR outperforms other state-of-the-art methods.
入藏号: WOS:000456936500022
PubMed ID: 30307858
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Wang, Qi                  0000-0002-7028-4956
Nie, Feiping                  0000-0002-0871-6519
Li, Xuelong                  0000-0002-0019-4197

ISSN: 0196-2892
eISSN: 1558-0644
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第 297 条,共 344 条
标题: Semisupervised Learning With Parameter-Free Similarity of Label and Side Information
作者: Zhang, R (Zhang, Rui); Nie, FP (Nie, Feiping); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 卷: 30 期: 2 页: 405-414 DOI: 10.1109/TNNLS.2018.2843798 出版年: FEB 2019
摘要: As for semisupervised learning, both label information and side information serve as pivotal indicators for the classification. Nonetheless, most of related research works utilize either label information or side information instead of exploiting both of them simultaneously. To address the referred defect, we propose a graph-based semisupervised learning (GSL) problem according to both given label information and side information. To solve the GSL problem efficiently, two novel self-weighted strategies are proposed based on solving associated equivalent counterparts of a GSL problem, which can be widely applied to a spectrum of biobjective optimizations. Different from a conventional technique to amalgamate must-link and cannotlink into a single similarity for convenient optimization, we derive a new parameter-free similarity, upon which intrinsic graph and penalty graph can be separately developed. Consequently, a novel semisupervised classification algorithm can be summarized correspondingly with a theoretical analysis.
入藏号: WOS:000457114600007
PubMed ID: 29994723
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Nie, Feiping         B-3039-2012         
Zhang, Rui         U-4639-2017         0000-0001-9418-0863
Li, Xuelong                  0000-0002-0019-4197
Nie, Feiping                  0000-0002-0871-6519

ISSN: 2162-237X
eISSN: 2162-2388
________________________________________
第 298 条,共 344 条
标题: Second-order statistical properties of a J(0)-correlated Schell-model beam in a turbulent atmosphere
作者: Yuan, YS (Yuan, Yangsheng); Liu, XL (Liu, Xianlong); Qu, J (Qu, Jun); Yao, M (Yao, Min); Gao, YR (Gao, Yaru); Cai, YJ (Cai, Yangjian)
来源出版物: JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 卷: 224 页: 185-191 DOI: 10.1016/j.jqsrt.2018.11.021 出版年: FEB 2019
摘要: We derive the analytical expressions for the second-order moments of the Wigner distribution function of a J(0)-correlated Schell-model (JCSM) beam propagating in a turbulent atmosphere. With the help of the second-order moments, we explore the second-order statistical properties (i.e., the M-2-factor, the effective radius of curvature and the Rayleigh range) of a JCSM beam propagating in a turbulent atmosphere for different turbulence parameters and beam parameters. It is found that the statistical properties of the JCSM beam are closely related to the initial beam parameters and turbulence parameters, and we can mitigate the negative effect of the turbulence by choosing suitable initial beam parameters. Our results will be useful for long distance free-space optical communications. (C) 2018 Elsevier Ltd. All rights reserved.
入藏号: WOS:000456754800021
ISSN: 0022-4073
eISSN: 1879-1352
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第 299 条,共 344 条
标题: Hybrid phase-amplitude superoscillation element for nonscanning optical superresolution imaging
作者: Xie, QK (Xie, Qingkun); Jiang, YR (Jiang, Yanru); Liang, J (Liang, Jian); Qu, ES (Qu, Enshi); Ren, LY (Ren, Liyong)
来源出版物: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 卷: 36 期: 2 页: 196-201 DOI: 10.1364/JOSAA.36.000196 出版年: FEB 1 2019
摘要: In this paper, we report a nonscanning optical superresolution imaging method based on a hybrid phaseamplitude superoscillation element. Using the Chebyshev polynomials as a basis set on the superoscillation waveform, the optimal combination of these, representing the optimal focal-spot in the local field of view, is found by genetic algorithm. Our numerical calculations demonstrate that a subwavelength focal spot with a full width at half-maximum as small as 253 nm is realized, which has more than 30 times improvement in sidelobe suppression ratio, and crucially, a greatly extended needle with continuously shrunken focal spot is yielded, which allows a large imaging tolerance in the axial displacement of the object. We then present our simulated results of the superresolution imaging on sparse point objects and continuous objects, where the practicality and effectiveness of this method are analyzed and discussed in detail. (c) 2019 Optical Society of America.
入藏号: WOS:000457453800015
PubMed ID: 30874098
ISSN: 1084-7529
eISSN: 1520-8532
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第 300 条,共 344 条
标题: High-dimensional one-way quantum processing implemented on d-level cluster states
作者: Reimer, C (Reimer, Christian); Sciara, S (Sciara, Stefania); Roztocki, P (Roztocki, Piotr); Islam, M (Islam, Mehedi); Cortes, LR (Cortes, Luis Romero); Zhang, YB (Zhang, Yanbing); Fischer, B (Fischer, Bennet); Loranger, S (Loranger, Sebastien); Kashyap, R (Kashyap, Raman); Cino, A (Cino, Alfonso); Chu, ST (Chu, Sai T.); Little, BE (Little, Brent E.); Moss, DJ (Moss, David J.); Caspani, L (Caspani, Lucia); Munro, WJ (Munro, William J.); Azana, J (Azana, Jose); Kues, M (Kues, Michael); Morandotti, R (Morandotti, Roberto)
来源出版物: NATURE PHYSICS 卷: 15 期: 2 页: 148-+ DOI: 10.1038/s41567-018-0347-x 出版年: FEB 2019
摘要: Taking advantage of quantum mechanics for executing computational tasks faster than classical computers(1) or performing measurements with precision exceeding the classical limit(2,3) requires the generation of specific large and complex quantum states. In this context, cluster states(4) are particularly interesting because they can enable the realization of universal quantum computers by means of a 'one-way' scheme(5), where processing is performed through measurements(6). The generation of cluster states based on sub-systems that have more than two dimensions, d-level cluster states, provides increased quantum resources while keeping the number of parties constant(7), and also enables novel algorithms(8). Here, we experimentally realize, characterize and test the noise sensitivity of three-level, four-partite cluster states formed by two photons in the time(9) and frequency(10) domain, confirming genuine multi-partite entanglement with higher noise robustness compared to conventional two-level cluster states(6,11-13). We perform proof-of-concept high-dimensional one-way quantum operations, where the cluster states are transformed into orthogonal, maximally entangled d-level two-partite states by means of projection measurements. Our scalable approach is based on integrated photonic chips(9,10) and optical fibre communication components, thus achieving new and deterministic functionalities.
入藏号: WOS:000457492900016
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Munro, William J         A-8453-2011         0000-0003-1835-2250
Caspani, Lucia         C-3777-2009         0000-0003-2711-0448
Chu, Sai T         D-3312-2014         0000-0001-8263-8507
Fischer, Bennet                  0000-0002-1186-0167
Romero Cortes, Luis         H-6185-2018         0000-0002-9534-4476

ISSN: 1745-2473
eISSN: 1745-2481
第 301 条,共 344 条
标题: Generation of coexisting high-energy pulses in a mode-locked all-fiber laser with a nonlinear multimodal interference technique
作者: Chen, GW (Chen, Guangwei); Li, WL (Li, Wenlei); Wang, GM (Wang, Guomei); Zhang, WF (Zhang, Wenfu); Zeng, C (Zeng, Chao); Zhao, W (Zhao, Wei)
来源出版物: PHOTONICS RESEARCH 卷: 7 期: 2 页: 187-192 DOI: 10.1364/PRJ.7.000187 出版年: FEB 1 2019
摘要: We demonstrate a passively mode-locked all-fiber laser incorporating a piece of graded-index multimode fiber as a mode-locking modulator based on a nonlinear multimodal interference technique, which generates two types of coexisting high-energy ultrashort pulses [i.e., the conventional soliton (CS) and the stretched pulse (SP)]. The CS with pulse energy as high as 0.38 nJ is obtained at the pump level of 130 mW. When the pump increases to 175 mW, the high-energy SP occurs at a suitable nonlinear phase bias and its pulse energy can reach 4 nJ at a 610 mW pump. The pulse durations of the generated CS and SP are 2.3 ps and 387 fs, respectively. The theory of nonlinear fiber optics, single-shot spectral measurement by the dispersive Fourier-transform technique, and simulation methods based on the Ginzburg-Landau equation are provided to characterize the laser physics and reveal the underlying principles of the generated CS and SP. A rogue wave, observed between the CS and SP regions, mirrors the laser physics behind the dynamics of generating a high-energy SP from a CS. The proposed all-fiber laser is versatile, cost-effective and easy to integrate, which provides a promising solution for high-energy pulse generation. (C) 2019 Chinese Laser Press
入藏号: WOS:000457501900013
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zeng, Chao                  0000-0003-0097-6399

ISSN: 2327-9125
________________________________________
第 302 条,共 344 条
标题: Nonlinear multimodal interference for ytterbium-doped all-fiber mode-locking noise-like pulse generation
作者: Lv, ZG (Lv, Zhiguo); Yang, Z (Yang, Zhi); Song, DD (Song, DongDong); Li, F (Li, Feng); Yang, XJ (Yang, Xiaojun); Yang, Y (Yang, Yang); Wang, YS (Wang, Yishan); Li, QL (Li, Qianglong); Zhao, W (Zhao, Wei)
来源出版物: APPLIED PHYSICS EXPRESS 卷: 12 期: 2 文献号: 022004 DOI: 10.7567/1882-0786/aaf417 出版年: FEB 2019
摘要: This work demonstrates the generation of the noise-like pulse (NLP) in an all-normal-dispersion passively mode-locked ytterbium-doped ring laser cavity with nonlinear multimodal interference as an equivalent all-fiber saturable absorber, for the first time to the best of our knowledge. Depending on the appropriate optimization of the intra-cavity birefringence and reasonable control of the curving curvature of the multimode fiber, self-started NLP operation can be built and maintained within a wide pump range. Additionally, the effect of the multimode fiber length on the NLP mode-locking performance and the generation of the high power NLP have also been experimentally studied. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000456007100001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
qianglong, li         V-6278-2019         

ISSN: 1882-0778
eISSN: 1882-0786
________________________________________
第 303 条,共 344 条
标题: Simultaneous Wavelength and Format Conversions Based on the Polarization-Insensitive FWM in Free-Space Optical Communication Network
作者: Huang, XN (Huang, Xinning); Suh, YL (Suh, Yulong); Duan, T (Duan, Tao); Hu, H (Hu, Hui); Xu, X (Xu, Xin); Xie, XP (Xie, Xiaoping)
来源出版物: IEEE PHOTONICS JOURNAL 卷: 11 期: 1 文献号: 6500208 DOI: 10.1109/JPHOT.2018.2888621 出版年: FEB 2019
摘要: Free-space optical (FSO) network is an effective way to enhance the interoperability and improve the resource utilization of the FSO communication systems. Since the structure is relatively simple and the nodes are not so many, wavelength conversion-based optical circuit switching (WC-OCS) is an appropriate candidate for the FSO network to solve the blocking problem. Meanwhile, format conversion to lower the data rate is also necessary in case the atmospheric channel deteriorates. In this paper, we construct a 3-node FSO network and experimentally investigate the feasibility of simultaneous WC-OCS and format conversion based on straight-lined single-pump four-wave mixing (FWM) process. The biterror-ratio (BER) results of the on-off key, binary phase-shift keying (BPSK), and quadrature phase-shift keying (QPSK) signals show that comparing to the corresponding back-to-back (B2B) transmission at the reference BER level of 10(-7), power penalties caused by WC-OCS are less than 1-dB for all the three formats. In the format conversion experiment from QPSK to BPSK, the power penalties, comparing to the original BPSK signal after B2B and WC-OCS transmission, are also less than 1 dB at the 10(-7) reference BER level. Consequently the feasibility and practicability of the FWM-based optical signal processing at FSO network nodes are experimentally validated.
入藏号: WOS:000455430100001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Huang, Xinning                  0000-0002-0610-4551

ISSN: 1943-0655
eISSN: 1943-0647
________________________________________
第 304 条,共 344 条
标题: Research on Applications of FastICA Algorithm in the Detection of Dangerous Liquids
作者: Zhou, DM (Zhou, Dongmei); Qiu, S (Qiu, Shi); Tan, JH (Tan, Jiahai); Li, XF (Li, Xiaofeng); Chen, C (Chen, Chen)
来源出版物: INTERNATIONAL JOURNAL OF PATTERN RECOGNITION AND ARTIFICIAL INTELLIGENCE 卷: 33 期: 2 文献号: 1958003 DOI: 10.1142/S0218001419580035 出版年: FEB 2019
摘要: In the actual environment of security detection, many kinds of liquids often exist in the same detection background, and their dangerous levels are difficult to identify. Therefore, it is very important to research on identifying the dangerous levels of various liquids. The paper establishes the S-parameter database of tested samples under specific detection environment with free space method. In the actual detection, ultra-wide-band (UWB) centimeter wave is used to measure the S-parameters of several detected liquids first. Then the fast independent component analysis (FastICA) algorithm is used for unmixing the mixed signal by Newton's iteration method and the negative entropy maximization search principle. The unmixed signal matches with the sample database adaptively, so the dangerous levels of the detected liquids are identified. Multiple experiments show that FastICA algorithm can reach a matching rate of 95% between water and 90# gasoline or alcohol and 90# gasoline, it also can reach a matching rate of around 73% between water and alcohol. This algorithm has a quick response and high reliability for identification of dangerous liquids. FastICA algorithm in this paper is applied for detecting the dangerous liquids for the first time, and it has high application value.
入藏号: WOS:000448268200010
ISSN: 0218-0014
eISSN: 1793-6381
________________________________________
第 305 条,共 344 条
标题: Optimized design of an emerging optical imager using compressive sensing
作者: Liu, G (Liu, Gang); Wen, DS (Wen, Desheng); Song, ZX (Song, Zongxi); Li, ZX (Li, Zhixin); Zhang, WK (Zhang, Weikang); Wei, X (Wei, Xin)
来源出版物: OPTICS AND LASER TECHNOLOGY 卷: 110 特刊: SI 页: 158-164 DOI: 10.1016/j.optlastec.2018.08.046 出版年: FEB 2019
摘要: The emerging optical imager utilizes Fourier-domain interferometry and can reduce system weight, size and power by an order of magnitude compared to conventional optical telescopes at the same resolution. The compressive sensing theory demonstrates that incomplete and noisy measurements may actually suffice for accurate reconstruction of compressible or sparse signals. In this paper, we propose an optimized design of the emerging optical imager based on compressive sensing theory. It simplifies data acquisition structure and reduces data transmission burden. In addition, the system robustness is improved.
入藏号: WOS:000449898000021
ISSN: 0030-3992
eISSN: 1879-2545
________________________________________
第 306 条,共 344 条
标题: High-performance mid-infrared frequency upconversion in lithium niobate waveguide patterned with metasurfaces
作者: Chi, J (Chi, Jiao); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu)
来源出版物: JOURNAL OF PHYSICS D-APPLIED PHYSICS 卷: 52 期: 3 文献号: 035101 DOI: 10.1088/1361-6463/aaebe7 出版年: JAN 16 2019
摘要: Mid-infrared detectors which converter the detected mid-infrared light to the near infrared (NIR) or even visible are of significant interest in free-space communication. We demonstrate a high-performance frequency upconversion from 3.4 mu m to 1.064 mu m pumped by 1.55 mu m in gradient metasurface-assisted thin-film lithium niobate waveguide. Based on this new structure of nonlinear waveguide, the phase-matching condition can be free in on-chip frequency conversion and the power of idler can be 24.5 times as high as that of no metasurface waveguide. The efficient upconversion is realized within a wide signal wavelength range from 3.25 mu m to 3.50 mu m. This study is helpful for obtaining the precise and integrated mid-infrared detectors.
入藏号: WOS:000450224600001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
, Chi                  0000-0002-0612-1431

ISSN: 0022-3727
eISSN: 1361-6463
________________________________________
第 307 条,共 344 条
标题: Feasibility of hyperspectral analysis for discrimination of rabbit liver VX2 tumor
作者: Duan, F (Duan, Feng); Yuan, J (Yuan, Jing); Liu, X (Liu, Xuan); Cui, L (Cui, Li); Bai, YH (Bai, Yan-Hua); Li, XH (Li, Xiao-Hui); Xu, HR (Xu, Huang-Rong); Liu, CY (Liu, Chen-Yang); Yu, WX (Yu, Wei-Xing)
来源出版物: WORLD JOURNAL OF GASTROINTESTINAL ONCOLOGY 卷: 11 期: 1 页: 1-8 DOI: 10.4251/wjgo.v11.i1.1 出版年: JAN 15 2019
摘要: BACKGROUND
Hepatocellular carcinoma is one of the most common malignant tumors worldwide. Currently, the most accurate diagnosis imaging modality for hepatocellular carcinoma is enhanced magnetic resonance imaging. However, it is still difficult to distinguish cirrhosis lesions, and novel diagnosis modalities are still needed.
AIM
To investigate the feasibility of hyperspectral analysis for discrimination of rabbit liver VX2 tumor.
METHODS
In this study, a rabbit liver VX2 tumor model was established. After laparotomy, under direct view, VX2 tumor tissue and normal liver tissue were subjected to hyperspectral analysis.
RESULTS
The spectral signature of the liver tumor was clearly distinguishable from that of the normal tissue, simply from the original spectral curves. Specifically, two absorption peaks at 600-900 nm wavelength in normal tissue disappeared but a new reflection peak appeared in the tumor. The average optical reflection at the whole waveband of 400-1800 nm in liver tumor was higher than that of the normal tissue.
CONCLUSION
Hyperspectral analysis can differentiate rabbit VX2 tumors. Further research will continue to perform hyperspectral imaging to obtain more information for differentiation of liver cancer from normal tissue.
入藏号: WOS:000455917100001
PubMed ID: 30984345
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Yu, Weixing         G-3658-2012         0000-0002-3216-526X

ISSN: 1948-5204
________________________________________
第 308 条,共 344 条
标题: Research on frequency modulation character of the current driven DFB semiconductor laser
作者: Zhang, J (Zhang, Jian); Gao, CX (Gao, Cunxiao); Xue, MY (Xue, Mingyuan); Liu, RS (Liu, Ruisheng)
来源出版物: MODERN PHYSICS LETTERS B 卷: 33 期: 1 文献号: 1850422 DOI: 10.1142/S0217984918504225 出版年: JAN 10 2019
摘要: This paper presents a study on the issue of current-driven distributed feedback (DFB) semiconductor lasers (LD) experiencing nonlinear laser frequency variation in the course of linear frequency modulation. A theoretical model of the linear frequency modulation process of DFB semiconductor lasers is established. On this basis, the relationship between injection current and laser frequency is analyzed and a correction method has been put forward, to improve the linearity of the laser frequency variation. It was eventually verified that the proposed correction method can greatly improve the linearity of the linear frequency modulation (LFM) output laser signal.
入藏号: WOS:000456472700007
ISSN: 0217-9849
eISSN: 1793-6640
________________________________________
第 309 条,共 344 条
标题: Isolated Pulmonary Nodules Characteristics Detection Based on CT Images
作者: Qiu, S (Qiu, Shi); Guo, Q (Guo, Qiang); Zhou, DM (Zhou, Dongmei); Jin, Y (Jin, Yi); Zhou, T (Zhou, Tao); He, ZA (He, Zhen'an)
来源出版物: IEEE ACCESS 卷: 7 页: 165597-165606 DOI: 10.1109/ACCESS.2019.2951762 出版年: 2019
摘要: Pulmonary nodules are the main pathological changes of the lung. Malignant pulmonary nodules will be transformed into lung cancer, which is a serious threat to human health and life. Therefore, the detection of pulmonary nodules is of great significance to save lives. However, in the face of a large number of lung CT image sequences, doctors need to spend a lot of time and energy, and in the detection process will inevitably produce the problem of false detection and missed detection. Therefore, it is very necessary for computer-aided doctors to detect pulmonary nodules. It is difficult to segment pulmonary nodules accurately and recognize the characteristics of pulmonary nodules in CT images. A complete set of semi-automatic lung nodule extraction and feature identification system is established, which is in line with the doctor's diagnosis process. A segmentation algorithm of pulmonary nodules based on regional statistical information is proposed to extract pulmonary nodules accurately. This is the first time that dynamic time warping algorithm is applied in the field of image processing, focusing on the lung nodule boundary. On this basis, the recursive graph visualization model is established to realize the visualization of boundary similarity. Finally, in order to accurately identify the characteristics of pulmonary nodules, a video similarity distance discrimination system is introduced to quantify the similarity between the nodules to be examined and the pulmonary nodules in the database. The experimental results show that the algorithm can accurately identify the normal shape, lobulated shape and lobulated shape of pulmonary nodules. The average processing speed is 0.58s/nodule. To some extent, it can reduce the misdiagnosis caused by experience and fatigue.
入藏号: WOS:000498715400001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Jin, Yi                  0000-0001-8408-3816

ISSN: 2169-3536
________________________________________
第 310 条,共 344 条
标题: Sample and Structure-Guided Network for Road Crack Detection
作者: Wu, SY (Wu, Siyuan); Fang, J (Fang, Jie); Zheng, XT (Zheng, Xiangtao)
来源出版物: IEEE ACCESS 卷: 7 页: 130032-130043 DOI: 10.1109/ACCESS.2019.2940767 出版年: 2019
摘要: As an indispensable task for traffic management department, road maintenance has attracted much attention during the last decade due to the rapid development of traffic network. As is known, crack is the early form of many road damages, and repair it in time can significantly save the maintenance cost. In this case, how to detect crack regions quickly and accurately becomes a huge demand. Actually, many image processing technique based methods have been proposed for crack detection, but their performances can not meet our expectations. The reason is that, most of these methods use bottom features such as color and texture to detect the cracks, which are easily influenced by the varied conditions such as light and shadow. Inspired by the great successes of machine learning and artificial intelligence, this paper presents a sample and structure guided network for detecting road cracks. Specifically, the proposed network is based on U-Net architecture, which remains the details from input to output by using skip connection strategy. Then, because the scale of crack samples is much smaller than that of non-crack ones, directly using the conventional cross entropy loss can not optimize the network effectively. In this case, the Focal loss is utilized to address the model optimization problem. Additionally, we incorporate the self-attention strategy into the proposed network, which enhances its stability by encoding the 2-order information among different local regions into the final features. Finally, we test the proposed method on four datasets, three public ones with labels and a photographed one without labels, to validate its effectiveness. It is noteworthy that, for the photographed dataset, we design a series of image processing strategies such as contrast enhancement to improve the generalization capability of the proposed method.
入藏号: WOS:000487541200006
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
wu, siyuan                  0000-0002-9041-8587

ISSN: 2169-3536
________________________________________
第 311 条,共 344 条
标题: Quadruped Animal Moving Target Extraction and Background Reconstruction Algorithm
作者: Zhou, DM (Zhou, Dongmei); Qiu, S (Qiu, Shi); Li, N (Li, Ni); Li, ZZ (Li, Zhengzhou); Huang, YD (Huang, Yongdong)
来源出版物: REVISTA CIENTIFICA-FACULTAD DE CIENCIAS VETERINARIAS 卷: 29 期: 5 页: 1416-1424 出版年: 2019
摘要: With the rapid development of computer technology, video surveillance systems are spread all over the streets, bringing convenience to people's lives. Video is also becoming more and more intelligent. Among them, the identification, tracking and extraction of moving targets are the challenges faced by intelligent monitoring systems. Based on the movement of the quadruped, this paper proposes an algorithm for the extraction and background reconstruction of the quadruped animal Firstly, the moving target of the video sequence is detected by combining the background subtraction method and the interframe difference method, and then the target tracking is performed based on the moving target feature. In the extraction of moving targets, an algorithm for animal moving target extraction based on spatiotemporal saliency is proposed, and the background reconstruction based on probability and statistics theory is used. Through the experiments of two similar quadruped animals, such as dogs and wolves, the proposed method has better anti-interference and better results in the recognition and extraction of moving targets.
入藏号: WOS:000486984300038
ISSN: 0798-2259
________________________________________
第 312 条,共 344 条
标题: Star Identification Algorithm Based on Oriented Singular Value Feature and Reliability Evaluation Method
作者: Wei, X (Wei, Xin); Wen, DS (Wen, Desheng); Song, ZX (Song, Zongxi); Xi, JB (Xi, Jiangbo)
来源出版物: TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 卷: 62 期: 5 页: 265-274 DOI: 10.2322/tjsass.62.265 出版年: 2019
摘要: A full-sky autonomous star identification algorithm aimed at solving the "lost-in-space" problem is presented in this paper. It mainly consists of two steps: an initial match step and a reliability evaluation step. Oriented singular value feature matching is adopted to search for corresponding candidates of the stars detected in the initial match. After obtaining the stars' initial match results, an evaluation method is applied to estimate the reliability of candidates from the star voting results, acquiring the final unique matching of stars in the image. Experiments show that our algorithm is more robust to star position noise and magnitude noise than the two conventional algorithms. In the simulations, our algorithm achieves an identification rate of 97.0% with 2-pixel star position noise and 0.3 My star magnitude noise, and also performs well with false stars in the field of view. In addition, the memory requirement and identification time of our method are acceptable for actual engineering projects.
入藏号: WOS:000483071600003
ISSN: 0549-3811
________________________________________
第 313 条,共 344 条
标题: Instance-Level Embedding Adaptation for Few-Shot Learning
作者: Hao, FS (Hao, Fusheng); Cheng, J (Cheng, Jun); Wang, L (Wang, Lei); Cao, JZ (Cao, Jianzhong)
来源出版物: IEEE ACCESS 卷: 7 页: 100501-100511 DOI: 10.1109/ACCESS.2019.2906665 出版年: 2019
摘要: Few-shot learning aims to recognize novel categories from just a fewlabeled instances. Existing metric learning-based approaches perform classifications by nearest neighbor search in the embedding space. The embedding function is a deep neural network and usually shared by all novel categories. However, these brute approaches lack a fast adaptation mechanism like meta-learning when dealing with novel categories. To tackle this, we present a novel instance-level embedding adaptation mechanism, aiming at rapidly adapting embedding deep features to improve their generalization ability in recognizing novel categories. To this end, we design an Attention Adaptation Module to pull a query instance and its corresponding class center as close as possible. Note that, each query instance is pulled closer to its corresponding class center before performing nearest neighbor classifications. This instance-level reduction of intra-class distance increases the probability of correct classifications, and thus improves the generalization ability to embed deep features and promoting the performance. The extensive experiments are conducted on two benchmark datasets: miniImageNet and CUB. Our approach yields very promising results on both datasets. In addition, in a realistic cross-domain evaluation setting, our method also achieves the-state-of-the-art performance.
入藏号: WOS:000481688500001
ISSN: 2169-3536
________________________________________
第 314 条,共 344 条
标题: A Novel Double-Index-Constrained, Multi-view, Fuzzy-Clustering Algorithm and Its Application for Detecting Epilepsy Electroencephalogram Signals
作者: Zhu, JQ (Zhu, Jiaqi); Li, K (Li, Kang); Xia, KJ (Xia, Kaijian); Gu, XQ (Gu, Xiaoqing); Xue, J (Xue, Jing); Qiu, S (Qiu, Shi); Jiang, YZ (Jiang, Yizhang); Qian, PJ (Qian, Pengjiang)
来源出版物: IEEE ACCESS 卷: 7 页: 103823-103832 DOI: 10.1109/ACCESS.2019.2931695 出版年: 2019
摘要: When processing a multi-view, epilepsy electroencephalogram (EEG) dataset, the traditional single-view clustering algorithms cannot fully mine the correlation information between each view and identify the importance of each view because of the limitations of its own methods. This limitation causes poor clustering performance when using these classic, single-view clustering algorithms. To solve this problem, a novel double-index-constrained, multi-view, fuzzy clustering algorithm (DIC-MV-FCM) is proposed for the automatic detection of epilepsy EEG data. The DIC-MV-FCM algorithm is integrated into the multi-view clustering technology and the view-weighted adaptive learning strategy, which can effectively use the correlation information between each view and control the importance of each view to improve the final clustering performance. The experimental results using several epilepsy EEG datasets show that the proposed DIC-MV-FCM algorithm has better clustering performance than the traditional clustering algorithms for processing multi-view EEG data.
入藏号: WOS:000481692400016
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
gu, xiaoqing                  0000-0001-9942-0651

ISSN: 2169-3536
________________________________________
第 315 条,共 344 条
标题: Beam pointing analysis and a novel coarse pointing assembly design in space laser communication
作者: Zhang, FR (Zhang Fu Rui); Han, JF (Han Jun-feng); Ruan, P (Ruan Ping)
来源出版物: OPTIK 卷: 189 页: 130-147 DOI: 10.1016/j.ijleo.2019.05.079 出版年: 2019
摘要: Nowadays, Small satellites take with high precision and lightweight laser communication terminals become a hot research direction. In this work, factors affecting beam pointing performance have been studied and a novel coarse pointing assembly (CPA) is designed based on flexure technology. The beam pointing performance is influenced by three aspects: Rayleigh distribution pointing error composed of static bias error and dynamic jitter, coupled motion between optical terminal and satellite and point ahead angle. Based on beam pointing requirements, a novel 2-D spatial flexure parallel coarse pointing assembly is proposed. Firstly, the type synthesis of this mechanism is performed and the freedom is verified by screw method. Then the detailed structural design is given. The pivotal component-elliptic arc flexure hinge is optimized by genetic algorithm and its rotation accuracy is less than 10 um. A flexure rod is used in actuating legs which is made rigid by spatial pseudo-rigid body method in kinematic analysis process. Finally, both of forward kinematics and inverse kinematics have been mathematically analyzed and the virtual prototype simulation is performed in Adams. The rotational accuracy can reach to 3 mu rad. The position, velocity and acceleration motion curves shown that the platform moves stable which means it's easy to control. This work provides a new idea for future design of space optical communication terminal.
入藏号: WOS:000481976900017
ISSN: 0030-4026
________________________________________
第 316 条,共 344 条
标题: An analytical model to predict the sizes of modified layer in glass with femtosecond Bessel beam
作者: Liao, K (Liao, Kai); Wang, WJ (Wang, Wenjun); Mei, XS (Mei, Xuesong); Cui, JL (Cui, Jianlei); Li, M (Li, Ming); Li, X (Li, Xun)
来源出版物: OPTIK 卷: 185 页: 232-241 DOI: 10.1016/j.ijleo.2019.03.071 出版年: 2019
摘要: Femtosecond Bessel beam is advantageous in high-quality glass cutting because of its resistance to diffraction. However, the sizes of the modified layer in the glass ablated by Bessel beam can be affected by many factors. In this study, an analytical model to predict the sizes(the depth and the maximum diameter) of modified layer in glass with femtosecond Bessel beam based on an axicon through an orthogonal experiment L-16(4(4)) was conducted. The coefficient values of four factors are obtained through the Matlab multiple linear regression function based on the experimental data. Simultaneously, the significance of the regression equation was tested by using the F-value test and the verification test. It found that the experimental results are consistent with the theoretical results. The combined processing parameters with the largest aspect ratio are determined through the range analysis and the influence of the various factors on the sizes was obtained. Finally, an application of thin glass cutting by the internal modification and breaking process is demonstrated. The glass is well cut with the chipping on the breaking edge < 10 mu m.
入藏号: WOS:000476692600032
ISSN: 0030-4026
________________________________________
第 317 条,共 344 条
标题: Application research of high-precision laser beam pointing technology in airborne aiming pod
作者: Xie, ML (Xie, Meilin); Liu, P (Liu, Peng); Ma, CW (Ma, Caiwen); Hao, W (Hao, Wei); Zhang, FR (Zhang, Furui); Huang, W (Huang, Wei); Lian, XZ (Lian, Xuezheng)
来源出版物: OPTIK 卷: 183 页: 775-782 DOI: 10.1016/j.ijleo.2019.02.152 出版年: 2019
摘要: Airborne aiming pod is mainly used for searching, capturing and tracking the target indicated by the laser, and then dropping the laser-guided weapons precisely to complete the close-range support attack or dual-aircraft cooperative instruction/attack. High-precision laser beam pointing technology is the core of the airborne aiming pod, and the accuracy of it is fatal for the realization of the final tactical index. In this paper, the factors affecting the beam pointing accuracy based on the research of airborne aiming pod platform are analyzed. At first, the composition of the pod system and the motion coupling of the composite axis pod are introduced; and then the beam pointing algorithm under the external guidance combined with aircraft disturbance and the effects of atmospheric turbulence and atmospheric attenuation on beam quality, including optical axis drift, beam spread and intensity distribution variation are discussed. Finally, the performance of the pod servo system is simulated and verified in Simulink. The simulation result of the real flight situation with disturbance moment shows that the pointing accuracy of the airborne aiming pod can reach 0.0075 degrees. The data analyzed in this paper can provide technical reference for other aiming photoelectric platforms.
入藏号: WOS:000471739300102
ISSN: 0030-4026
________________________________________
第 318 条,共 344 条
标题: Simulation of detecting piston error between segmented mirrors by Fizaeu interference technique on ZEMAX
作者: Wei, LM (Wei, Limin); Wang, CC (Wang, Chenchen); Duan, WR (Duan, Wenrui)
来源出版物: OPTIK 卷: 183 页: 828-834 DOI: 10.1016/j.ijleo.2019.02.097 出版年: 2019
摘要: The main method to improve the resolution of optical system is enlarging the pupil of optical system, and by using several segmented mirrors to get an equivalent large diameter primary mirror is a common way. After the deployment on orbit, there will be deviation between deployment position and the designed position, which is position error. The error determines the imaging quality of the optical system. So the precision of the position of segmented mirror is needed to be analyzed to make sure the error will not destroy the image quality. This paper uses Fizaeu interference technique to detect the piston error between segmented mirrors, and analyses the detect theory of it. Build model in the ZEMAX and simulate the change of stripe's position and brightness information. In the end, we get the same result of MATLAB, which testifies Fizaeu is of feasibility to detect the piston error.
入藏号: WOS:000471739300110
ISSN: 0030-4026
________________________________________
第 319 条,共 344 条
标题: Polarimetric imaging method for target enhancement in haze based on polarimetric retrieval
作者: Zhang, WF (Zhang, Wenfei); Liang, J (Liang, Jian); Xing, F (Xing, Fei); Man, ZS (Man, Zhongsheng); Ge, XL (Ge, Xiaolu); Fu, SG (Fu, Shenggui)
来源出版物: JOURNAL OF MODERN OPTICS 卷: 66 期: 11 页: 1235-1243 DOI: 10.1080/09500340.2019.1610520 出版年: 2019
摘要: Polarimetric imaging has been proven to be an effective way in detecting the targets of interest in complicated surroundings by analyzing the polarization property, instead of the intensity, of the light emanating from the objects. Unfortunately, polarimetric imaging encounters difficulty when the surroundings are very scattered, where on the one hand the polarization property of the object light usually becomes very faint after a strong depolarized scattering process; on the other hand, the object light will be blended with the atmospheric light scattered by haze particles (airlight). In this paper, we propose a polarimetric imaging retrieval method that can be used for such challenging conditions. Firstly, the airlight radiance is estimated precisely. Then, the airlight is removed from the hazy images. Finally, the residual polarization property of the object light is regained, which ensures the validity of the polarimetric imaging method in these conditions. The experiments confirm that the proposed method is useful in enhancing polarimetric imaging detection in haze.
入藏号: WOS:000471790800010
ISSN: 0950-0340
eISSN: 1362-3044
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第 320 条,共 344 条
标题: Convolutional Edge Constraint-Based U-Net for Salient Object Detection
作者: Han, L (Han, Le); Li, XL (Li, Xuelong); Dong, YS (Dong, Yongsheng)
来源出版物: IEEE ACCESS 卷: 7 页: 48890-48900 DOI: 10.1109/ACCESS.2019.2910572 出版年: 2019
摘要: The salient object detection is receiving more and more attention from researchers. An accurate saliency map will be useful for subsequent tasks. However, in most saliency maps predicted by existing models, the objects regions are very blurred and the edges of objects are irregular. The reason is that the hand-crafted features are the main basis for existing traditional methods to predict salient objects, which results in different pixels belonging to the same object often being predicted different saliency scores. Besides, the convolutional neural network (CNN)-based models predict saliency maps at patch scale, which causes the objects edges of the output to be fuzzy. In this paper, we attempt to add an edge convolution constraint to a modified U-Net to predict the saliency map of the image. The network structure we adopt can fuse the features of different layers to reduce the loss of information. Our SalNet predicts the saliency map pixel-by-pixel, rather than at the patch scale as the CNN-based models do. Moreover, in order to better guide the network mining the information of objects edges, we design a new loss function based on image convolution, which adds an L1 constraint to the edge information of saliency map and ground-truth. Finally, experimental results reveal that our SalNet is effective in salient object detection task and is also competitive when compared with 11 state-of-the-art models.
入藏号: WOS:000467528000001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         

ISSN: 2169-3536
________________________________________
第 321 条,共 344 条
标题: Investigation of isolation for free space laser communication in the mono-wavelength optical T/R channels
作者: Xia, FY (Xia, Fangyuan); Yang, JF (Yang, Jianfeng); Yao, ZS (Yao, Zhoushi); Song, YS (Song, Yansong); Ren, LX (Ren, Lanxu); Tan, QG (Tan, Qinggui)
来源出版物: OPTIK 卷: 181 页: 738-747 DOI: 10.1016/j.ijleo.2018.12.090 出版年: 2019
摘要: Favorable isolation performance in optical transmitting-receiving (T/R) channels is key to establishing full-duplex bi-directional laser communication links when designing mono-wavelength laser communication terminals. This study proposes a novel design scheme for T/R channels that use a single laser wavelength. The system includes measures such as the deflection at lambda/4 wave plate angles, light trap installation at a polarization beam splitter, and removal of polarization analyzers in optimized systems. A mathematical model describing isolation in the optical T/R channels is presented. Three types of factors that affect the isolation of optical T/R channels were analyzed and simulated in detail. The present simulation results show that the roughness of the lambda/4 wave plate and the solid angle of the detector field of view are exponentially related to T/R isolation, which can thus be regarded as the most significant factors affecting isolation. According to the present design scheme, the prototype T/R channel was developed for measuring isolation. The measured value (77.8 dB) agrees well with the result determined using the established mathmatical model (77.3 dB). Conclusively, the present theoretical model can provideguidance for optimizing isolation in a mono-wavelength optical channel. Thus, it can be applied extensively in laser communication systems, including inter-satellite networks.
入藏号: WOS:000465157600095
ISSN: 0030-4026
________________________________________
第 322 条,共 344 条
标题: TERAHERTZ SPECTROSCOPIC INVESTIGATION OF SALICYLIC ACID AND SODIUM SALICYLATE
作者: Ding, L (Ding, L.); Fan, WH (Fan, W. -H.); Song, C (Song, C.); Chen, X (Chen, X.); Chen, ZY (Chen, Z. -Y.)
来源出版物: JOURNAL OF APPLIED SPECTROSCOPY 卷: 85 期: 6 页: 1143-1150 DOI: 10.1007/s10812-019-00773-w 出版年: JAN 2019
摘要: The terahertz spectra of salicylic acid and sodium salicylate are measured by broadband terahertz time-domain spectroscopy (THz-TDS). Two absorption features of salicylic acid and three characteristic features of sodium salicylate are reported for the first time. Our investigation shows that salicylic acid and sodium salicylate can be easily distinguished based on their distinctive THz spectra, which could be attributed to their intra- and intermolecular structure differences. Furthermore, solid-state density functional theory calculations reveal that the absorption features of salicylic acid mainly originate from intermolecular interactions, except for the absorption feature at 2.28 THz, while gaseous-state theory calculations show that the absorption features of sodium salicylate mainly come from intramolecular vibrations except for the absorption feature at 0.40 THz. Our investigation indicates that THz vibrational modes are highly sensitive to molecular structures and intermolecular interactions, promoting the application of THz spectroscopy in distinguishing chemicals and pharmaceuticals with similar molecular structures.
入藏号: WOS:000463906800025
ISSN: 0021-9037
eISSN: 1573-8647
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第 323 条,共 344 条
标题: Fuzzy Greenberger-Horne-Zeilinger state analyzer and multiparty measurement-device-independent quantum key distribution network
作者: Zhang, LT (Zhang, Litao); Hu, M (Hu, Min); Ran, P (Ran, Pan); Zeng, HY (Zeng, Hanyu); Li, J (Li, Jun); Guo, BH (Guo, Banghong)
来源出版物: OPTICAL ENGINEERING 卷: 58 期: 1 文献号: 016113 DOI: 10.1117/1.OE.58.1.016113 出版年: JAN 2019
摘要: Greenberger-Horne-Zeilinger (GHZ) state is an essential resource in quantum processing. We propose multiparty measurement-device-independent quantum key distribution (MDI-QKD) protocol based on a fuzzy GHZ state analyzer, which is composed of linear optical components. Our scheme requires only N detectors and N - 1 polarizing beam splitters to realize an N-party MDI-QKD network. From numerical simulations, the security communication distance is improved to 300 km, and key rate is determined to be higher than 10-14. Compared with the previous work, our scheme needs less optical components and detectors, is easier to extend more users, and narrows the gap between theory and practice in multiparty MDI-QKD network. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)
入藏号: WOS:000463893000050
ISSN: 0091-3286
eISSN: 1560-2303
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第 324 条,共 344 条
标题: Passively Q-Switched All-Fiber Yb-Doped Lasers Based on Nonlinear Multimode Interference(dagger)
作者: Zhao, FY (Zhao, Fengyan); Wang, HS (Wang, Hushan); Zhang, T (Zhang, Ting); Wang, YS (Wang, Yishan); Hu, XH (Hu, Xiaohong); Sun, CD (Sun, Chuandong); Zhang, W (Zhang, Wei)
来源出版物: JOURNAL OF RUSSIAN LASER RESEARCH 卷: 40 期: 1 页: 87-93 DOI: 10.1007/s10946-019-09774-8 出版年: JAN 2019
摘要: We report a passively Q-switched all-fiber Yb-doped laser using the structure of step-index multimode fiber and graded-index fiber (SIMF-GIMF) as a new saturable absorber (SA) based on the nonlinear multimode interference (NL-MMI). Through bending the SA to a certain state, we obtain a stable Q-switched laser operation with the shortest pulse duration of 4.37 s and a corresponding repetition rate of 147.6 kHz with center at 1,039 nm. The maximum average output power and single pulse energy are recorded to be 2.409 mW and 16.3 nJ, respectively. To the best of our knowledge, this paper confirms experimentally for the first time Q-switched laser operation based on SIMF-GIMF SA in all-fiber lasers. In addition, we also observed unstable Q-switched mode-locking operation. All-fiber lasers based on SIMF-GIMF SA are attractive for practical applications and undergo no damage and performance degradation with time.
入藏号: WOS:000461367900014
ISSN: 1071-2836
eISSN: 1573-8760
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第 325 条,共 344 条
标题: GETNET: A General End-to-End 2-D CNN Framework for Hyperspectral Image Change Detection
作者: Wang, Q (Wang, Qi); Yuan, ZH (Yuan, Zhenghang); Du, Q (Du, Qian); Li, XL (Li, Xuelong)
来源出版物: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 卷: 57 期: 1 页: 3-13 DOI: 10.1109/TGRS.2018.2849692 出版年: JAN 2019
摘要: Change detection (CD) is an important application of remote sensing, which provides timely change information about large-scale Earth surface. With the emergence of hyperspectral imagery, CD technology has been greatly promoted, as hyperspectral data with high spectral resolution are capable of detecting finer changes than using the traditional multispectral imagery. Nevertheless, the high dimension of the hyperspectral data makes it difficult to implement traditional CD algorithms. Besides, endmember abundance information at subpixel level is often not fully utilized. In order to better handle high-dimension problem and explore abundance information, this paper presents a general end-to-end 2-D convolutional neural network (CNN) framework for hyperspectral image CD (HSI-CD). The main contributions of this paper are threefold: 1) mixed-affinity matrix that integrates subpixel representation is introduced to mine more cross-channel gradient features and fuse multisource information; 2) 2-D CNN is designed to learn the discriminative features effectively from the multisource data at a higher level and enhance the generalization ability of the proposed CD algorithm; and 3) the new HSI-CD data set is designed for objective comparison of different methods. Experimental results on real hyperspectral data sets demonstrate that the proposed method outperforms most of the state of the arts.
入藏号: WOS:000455089000001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Li, Xuelong         Z-3785-2019         
Li, Xuelong                  0000-0002-0019-4197
Wang, Qi                  0000-0002-7028-4956

ISSN: 0196-2892
eISSN: 1558-0644
________________________________________
第 326 条,共 344 条
标题: Noise-resistant matching algorithm integrating regional information for low-light stereo vision
作者: Feng, HH (Feng, Huahui); Zhang, G (Zhang, Geng); Hu, BL (Hu, Bingliang); Zhang, X (Zhang, Xin); Li, SY (Li, Siyuan)
来源出版物: JOURNAL OF ELECTRONIC IMAGING 卷: 28 期: 1 文献号: 013050 DOI: 10.1117/1.JEI.28.1.013050 出版年: JAN 2019
摘要: Low-light stereo vision is a challenging problem because images captured in dark environment usually suffer from strong random noises. Some widely adopted algorithms, such as semiglobal matching, mainly depend on pixel-level information. The accuracy of local feature matching and disparity propagation decreases when pixels become noisy. Focusing on this problem, we proposed a matching algorithm that utilizes regional information to enhance the robustness to local noisy pixels. This algorithm is based on the framework of ADCensus feature and semiglobal matching. It extends the original algorithm in two ways. First, image segmentation information is added to solve the problem of incomplete path and improve the accuracy of cost calculation. Second, the matching cost volume is calculated with AD-SoftCensus measure that minimizes the impact of noise by changing the pattern of the census descriptor from binary to trinary. The robustness of the proposed algorithm is validated on Middlebury datasets, synthetic data, and real world data captured by a low-light camera in darkness. The results show that the proposed algorithm has better performance and higher matching rate among top-ranked algorithms on low signal-to-noise ratio data and high accuracy on the Middlebury benchmark datasets. (C) 2019 SPIE and IS&T
入藏号: WOS:000460119700050
ISSN: 1017-9909
eISSN: 1560-229X
________________________________________
第 327 条,共 344 条
标题: Tunable broadband emission from red to blue by gamma radiation in multicomponent phosphate glasses
作者: He, QL (He, Quanlong); Wang, PF (Wang, Pengfei); Li, WN (Li, Weinan); Sun, MY (Sun, Mengya); Lu, M (Lu, Min); Peng, B (Peng, Bo)
来源出版物: JOURNAL OF THE AMERICAN CERAMIC SOCIETY 卷: 102 期: 1 页: 48-52 DOI: 10.1111/jace.15986 出版年: JAN 2019
摘要: We demonstrate for the first time that the tunable broadband emission from red to blue can be obtained by gamma radiation in multicomponent phosphate glasses. Gamma radiation causes the increased phosphate-related non-bridging oxygen hole center and oxygen hole center defects, which lead to the enhanced emission peaking at 452 nm. Meanwhile, the vibration amplitude of O-P-O chain's internal decrease, resulting in the decreased emission at 660 nm. Besides, the increased isolated phosphate units (Q(0) and Q(1)), as well as the gradual decrease in P atoms that make up the main phosphate chain contribute to the blue-shift of the main emission peak at 616 nm, which directly results in the tunable broadband emission from 616 to 460 nm. The gamma radiation process endows this type of multicomponent phosphate glasses with promising applications in solid-state lighting devices.
入藏号: WOS:000459932500005
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Pengfei, Wang                  0000-0002-5285-9832

ISSN: 0002-7820
eISSN: 1551-2916
________________________________________
第 328 条,共 344 条
标题: Hyperspectral Anomaly Detection via Sparse Dictionary Learning Method of Capped Norm
作者: Yuan, Y (Yuan, Yuan); Ma, DD (Ma, Dandan); Wang, Q (Wang, Qi)
来源出版物: IEEE ACCESS 卷: 7 页: 16132-16144 DOI: 10.1109/ACCESS.2019.2894590 出版年: 2019
摘要: Hyperspectral anomaly detection is a research hot spot in the field of remote sensing. It can distinguish abnormal targets from the scene just by utilizing the spectral differences and requiring no prior information. A series of anomaly detectors based on Reed-Xiaoli methods are very important and typical algorithms in this research area, which generally have the hypothesis about background subject to the Gaussian distribution. However, this assumption is inaccurate to describe a hyperspectral image with a complex scene in practice. Besides, due to the unavoidable existence of abnormal targets, background statistics will be affected which will reduce the detection performance. To address these problems, we propose a sparse dictionary learning method by using a capped norm to realize hyperspectral anomaly detection. Moreover, a new training data selection strategy based on clustering technique is also proposed to learn a more representative background dictionary. The main contributions are concluded in threefold: 1) neither making any assumptions on the background distribution nor computing the covariance matrix, the proposed method is more adaptive to all kinds of complex hyperspectral images in practice; 2) owing to the good qualities of the capped norm, the learned sparse background dictionary is resistant to the effect of anomalies and has stronger distinctiveness to anomalies from background; 3) without using the traditional sliding hollow window technique, the proposed method is more effective to detect different sizes of abnormal targets. The extensive experiments on four commonly used real-world hyperspectral images demonstrate the effectiveness of the proposed method and show its superiority over the benchmark methods.
入藏号: WOS:000459445500001
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Wang, Qi                  0000-0002-7028-4956

ISSN: 2169-3536
________________________________________
第 329 条,共 344 条
标题: An Adaptive Stopping Active Contour Model for Image Segmentation
作者: Niu, YF (Niu, Yuefeng); Cao, JZ (Cao, Jianzhong); Zhou, ZF (Zhou, Zuofeng)
来源出版物: JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY 卷: 14 期: 1 页: 445-453 DOI: 10.1007/s42835-018-00030-8 出版年: JAN 2019
摘要: Active contour models (ACMs) are widely used in image segmentation applications. However, the selection of maximum iterations which controls the convergence of the ACMs is still a challenging problem. In this paper, an adaptive method for choosing the optimal number of iterations based on the local and global intensity fitting energy is proposed, which increases the automaticity of the active contour model. Moreover, the adoption of the reaction diffusion (RD) method instead of the distance regularization term can improve the accuracy and speed of segmentation effectively. Experimental results on synthetic and real images show that the proposed model outperforms other representative models in terms of accuracy and efficiency.
入藏号: WOS:000459450800042
ISSN: 1975-0102
eISSN: 2093-7423
________________________________________
第 330 条,共 344 条
标题: Phase Functions of Typical Lunar Surface Minerals Derived for the Hapke Model and Implications for Visible to Near-Infrared Spectral Unmixing
作者: Yang, YZ (Yang, Yazhou); Li, S (Li, Shuai); Milliken, RE (Milliken, Ralph E.); Zhang, H (Zhang, Hao); Robertson, K (Robertson, Kevin); Hiroi, T (Hiroi, Takahiro)
来源出版物: JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS 卷: 124 期: 1 页: 31-60 DOI: 10.1029/2018JE005713 出版年: JAN 2019
摘要: Laboratory spectrophotometric measurements of minerals common on the lunar surface (olivine, pyroxene, plagioclase, and ilmenite) are measured over a wavelength range of 0.4 to 2.5m to better understand the effects of the particle phase function (PF; P[g]) on the application of Hapke's radiative transfer model to reflectance spectra of lunar materials. One objective of this work is to determine if accounting for wavelength-dependent photometric effects can improve spectral estimates of mineral abundance in lunar materials, particularly that of ilmenite. We also discuss a two-step calibration method to correct for the non-Lambertian behavior and wavelength dependence of the common reference standard Spectralon. Both a two-term Legendre polynomial representation of the PF and the Henyey-Greenstein PF are examined. We use our results to apply the Hapke radiative transfer model to reflectance spectra of lab mixtures and test the effects of different PF characteristics and assumptions. Laboratory spectra indicate that ilmenite exhibits more backward scattering behavior compared with silicate minerals, which are more forward scattering. We find that the variations in PF can affect derived single-scattering albedo values and thus spectral unmixing results. Because single-scattering contribution dominates the reflectance properties of dark minerals such as ilmenite, large uncertainties in derived single-scattering albedo values can be introduced by small changes in PFs. However, it is observed that the use of a wavelength-dependent PF does not produce significant differences in spectral unmixing results for binary and ternary silicate mixtures.
Plain Language Summary Olivine, pyroxene, plagioclase, and ilmenite are common minerals on the lunar surface, and knowledge on their spatial and temporal distributions can help to understand the geological evolutions of our Moon. Remote sensing reflectance spectroscopy is an important technique that can be used to identify those minerals, because their reflectance spectra have different diagnostic absorption features. Since reflectance spectra could vary with the change of illumination and viewing angles, the accurate estimation of mineral concentrations using reflectance spectra would rely on light scattering models that quantitatively describe how light is scattered from the target surface. The purpose of this study is to understand the accuracy of retrieving mineral concentrations in ilmenite-bearing mixtures using the Hapke model widely used in quantitative analysis of reflectance spectra. We measured the reflectance spectra of the more transparent olivine, pyroxene, and plagioclase and the more opaque ilmenite at different viewing angles. Using these data, we quantified the scattering properties of these four minerals. We found that ilmenite is more backscattering while the other three minerals are more forward scattering. The mixing of these dark and bright materials makes the accurate interpretation of reflectance spectra data difficult. Our results suggest that well constrained scattering properties of the component minerals and their mixtures can help improve the accuracy of mineral abundance estimations.
入藏号: WOS:000459245700003
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Zhang, Hao         C-1704-2009         0000-0003-2902-1887
Li, Shuai         AAD-2098-2019         0000-0002-9885-0809
Yang, Yazhou         H-1646-2018         0000-0002-9848-4650

ISSN: 2169-9097
eISSN: 2169-9100
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第 331 条,共 344 条
标题: Spectral Tensor Synthesis Analysis for Hyperspectral Image Spectral-Spatial Feature Extraction
作者: Yan, RH (Yan, Ronghua); Peng, JY (Peng, Jinye); Ma, DM (Ma, Dongmei); Wen, DS (Wen, Desheng)
来源出版物: JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING 卷: 47 期: 1 页: 91-100 DOI: 10.1007/s12524-018-0873-0 出版年: JAN 2019
摘要: Feature extraction is a preprocessing step for hyperspectral image classification. Principal component analysis only uses the spectral information, but it does not use spatial information of a hyperspectral image. Both spatial and spectral information are used when hyperspectral image is modelled as tensor, that is, decreasing the noise on spatial dimension and reducing the dimension on a spectral dimension at the same time. However, in this model, a hyperspectral image is modelled only as a data cube. The factors affecting the spectral features of ground objects is not considered and these factors are barely distinguished. This means that further improving classification is very difficult. Therefore, a new model on hyperspectral image is proposed by the authors. In the new model, many factors that impact the spectral features of ground objects are synthesized as the within-class factor. The within-class factor, the class factor and the pixel spectral are selected as a mode, respectively. The pixel spectrals in the training set are modelled as a third-order tensor. The experiment results indicate that the new method improves the classification compared with the previous methods.
入藏号: WOS:000458258300009
ISSN: 0255-660X
eISSN: 0974-3006
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第 332 条,共 344 条
标题: Wide spectrum responsivity detectors from visible to mid-infrared based on antimonide
作者: Guo, CY (Guo, Chunyan); Sun, YY (Sun, Yaoyao); Jia, QX (Jia, Qingxuan); Jiang, Z (Jiang, Zhi); Jiang, DW (Jiang, Dongwei); Wang, GW (Wang, Guowei); Xu, YQ (Xu, Yingqiang); Wang, T (Wang, Tao); Tian, JS (Tian, Jinshou); Wu, ZX (Wu, Zhaoxin); Niu, ZC (Niu, Zhichuan)
来源出版物: INFRARED PHYSICS & TECHNOLOGY 卷: 96 页: 1-6 DOI: 10.1016/j.infrared.2018.10.037 出版年: JAN 2019
摘要: A kind of wide spectrum Infrared detectors based on InAs/GaSb type-II superlattices (T2SLs) operating from 0.5 mu m to 5 mu m wavelength range is reported. The materials were grown by Molecular Beam Epitaxy (MBE) on GaSb substrates. Diverse types and sizes microstructure are fabricated on the surface of the detector to form the photon traps (PTs) array. PTs decrease the reflectivity and increase the light absorption of epitaxial material. Compared with the planar mesa detectors without antireflection (AR) film, detectors with PTs array exhibits a high responsivity of 0.86 A/W at 1160 nm and maximum D-star reaches to 10(9) cm Hz(1/2)/W in visible wavelength. Also, the PTs processed on detector augment spectral response and QE in infrared wavelength. The peak responsivity of the detector with PTs is to 1.35 A/W and QE can exceed to 0.76 in the infrared wavelength. The infrared detector with PTs is attractive for numerous applications.
入藏号: WOS:000457664300001
ISSN: 1350-4495
eISSN: 1879-0275
________________________________________
第 333 条,共 344 条
标题: Two-dimensional simulation of dielectric barrier discharge with ring electrodes at atmospheric pressure
作者: Wang, J (Wang, Jing); Lei, BY (Lei, Bingying); Li, J (Li, Jing); Xu, YG (Xu, Yonggang); Zhang, JY (Zhang, Jingyue); Tang, J (Tang, Jie); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei); Duan, YX (Duan, Yixiang)
来源出版物: PHYSICS OF PLASMAS 卷: 26 期: 1 文献号: 013511 DOI: 10.1063/1.5077079 出版年: JAN 2019
摘要: A two-dimensional fluid model was used to investigate the characteristics of helium dielectric barrier discharge (DBD) equipped with ring electrodes at atmospheric pressure. Simulation results show that the transition of discharge also exists as the traditional parallel-plate DBD. The discharge mode translates from the Townsend mode to the glow mode during the rising phase and returns to the Townsend mode in the falling phase of the discharge. Meanwhile, symmetric discharge current and current densities at different radial positions are observed in each cycle, and the current density peak at the radial center of the ring electrode is always higher than that at other positions. In addition, the charged particles follow a periphery-advantage spatial distribution, and the relative temporal variation of charged particles is faster in the periphery than in the central region because of the higher electric field existing there. Moreover, the density of surface charges assembled in the periphery changes faster than that in the central region of the upper dielectric barrier and exhibits an uneven periphery-advantage distribution, which is also ascribed to the higher electric field in the periphery resulted from the ring electrode configuration. Comparing the ring electrode DBD with the traditional one indicates that an inverse discharge structure is observed between the two electrode configurations. Published under license by AIP Publishing.
入藏号: WOS:000457410900072
ISSN: 1070-664X
eISSN: 1089-7674
________________________________________
第 334 条,共 344 条
标题: Dynamically Tunable and High-Contrast Graphene-Based Terahertz Electro-Optic Modulator
作者: Li, SP (Li, Shao-Peng); Zhou, J (Zhou, Jing); Yin, RL (Yin, Rui-Ling); Sun, QB (Sun, Qi-Bing)
来源出版物: COMMUNICATIONS IN THEORETICAL PHYSICS 卷: 71 期: 1 页: 97-102 DOI: 10.1088/0253-6102/71/1/97 出版年: JAN 2019
摘要: We propose and discuss terahertz (THz) electro-optic modulator induced by periodically patterned graphene micro cavity. Due to the joint effect of graphene plasmon resonances and Fabry-Perot (F-P) oscillations, plasmon-induced transparency (PIT) effect is achieved and the operation frequency can be dynamically tuned by graphene Fermi energies and structural parameters. The results reveal that modulation depth (MD) larger than 80% is obtained across a wide frequency range from 4.2 THz to 9.4 THz, and the largest MD and Q factor reaches 95% and 15.8, respectively. In addition, operation frequency range and MD can also be tuned by optimizing the structure parameters. This investigation promises the development of high-performance widely tunable THz modulator in chip integrated photonic circuits.
入藏号: WOS:000456842600013
ISSN: 0253-6102
eISSN: 1572-9494
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第 335 条,共 344 条
标题: Preparation and Photoluminescence Properties of Fluorophosphate Glasses with High Efficient White Light Emission
作者: Zheng, JJ (Zheng Jia-jin); Lu, Q (Lu Qiang); Zheng, RL (Zheng Rui-lin); Zou, H (Zou Hui); Yu, KH (Yu Ke-han); Wei, W (Wei Wei)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS 卷: 39 期: 1 页: 39-44 DOI: 10.3964/j.issn.1000-0593(2019)01-0039-06 出版年: JAN 2019
摘要: A series of Sn2+, Dy3+ and Sn2+-Dy3+ co-doped fluorophosphate glasses (FPGs) for white light emitting phosphor have been prepared by the melt quenching method. Under the UV light excitation, FPG : Sn2+ and FPG : Dy3+ can obtain blue and yellow light, respectively. The emission color of FPG : Sn2+-DY3+ can be tuned from blue to white color by properly adjusting the concentration of Dy3+ ions under the excitation of 280 nm UV light, which can be attributed to the energy transfer from Sn2+ to Dy3+ ions. The energy transfer mechanism was investigated and analyzed according to the photoluminescence, lifetime decay and CIE chromaticity coordinate. In addition, the FPG : Sn2+ fluorophosphate glass shows the highest color rendering index of 94 and the quantum efficiency of 81.3%, and the Sn2+-Dy3+ co-doped fluorophosphate glasses show better white color coordinates. By controlling the concentration of Dy3+, the FPGs can present a white light with a CIE chromaticity coordinate of (0.3111, 0.330), which is very close to the equal energy point. The corresponding quantum efficiency and the luminance are 56.3% and 6 706 cd.m(-2), respectively. The results of this study demonstrate that the FPGs are promising candidate for commercial white light emitting applications.
入藏号: WOS:000456357000007
ISSN: 1000-0593
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第 336 条,共 344 条
标题: A Fast Lossless Data Compression Method for the Wedge Filter Spectral Imager
作者: Li, HB (Li Hong-bo); Hu, BL (Hu Bing-liang); Yu, L (Yu Lu); Wei, RY (Wei Rui-yi); Yu, T (Yu Tao)
来源出版物: SPECTROSCOPY AND SPECTRAL ANALYSIS 卷: 39 期: 1 页: 297-302 DOI: 10.3964/j.issn.1000-0593(2019)01-0297-06 出版年: JAN 2019
摘要: Wedge filter spectral imager, with no moving components and low complexity, has become an important development direction of low cost miniature imaging spectrometer. Based on the state of the art hyperspectral lossless compression standard CCSDS123, we propose a lossless data compression method for the wedge filter spectral imager. The proposed method redefines the local difference vector in CCSDS123, taking fully advantage of the spatial -spectral co -modulation characteristics of the wedge filter spectral imager. To compress the raw data from a wedge filter spectral imager, the compression encoder firstly predicts the sample value using its local sum and local difference vector, then computes a prediction residual and the corresponding mapped prediction residual, finally encodes the mapped prediction residual via a sample -adaptive entropy coding approach. The proposed method can effectively compress the raw data from a wedge filter spectral imager by using the local correlation in the spatial -spectral space. To verify the compression performance of the proposed method, experiments are taken on 6 raw datasets containing different scenes. The results show that the proposed method surpasses the original CCSDS123 method by about 21. 62% higher compression ratio on the test datasets with almost the same computational time.
入藏号: WOS:000456357000046
ISSN: 1000-0593
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第 337 条,共 344 条
标题: Design and Electrical Analysis of Multi-Electrode Cylindrical Dielectric Barrier Discharge Plasma Reactor
作者: Niu, GH (Niu, Guanghui); Guo, GM (Guo, Guangmeng); Tang, J (Tang, Jie); Li, YP (Li, Yanping); Wang, X (Wang, Xu); Duan, YX (Duan, Yixiang)
来源出版物: IEEE TRANSACTIONS ON PLASMA SCIENCE 卷: 47 期: 1 页: 419-426 DOI: 10.1109/TPS.2018.2883944 子辑: 3 出版年: JAN 2019
摘要: Dielectric barrier discharges (DBDs), due to its unique advantages such as simple design and low operation cost, have gained more and more attention all over the world. However, traditional plasma reactor can always have capacitive current with high peak values, which limits its further application in fields such as plasma catalytic reactions and surface treatment. In this proposed work, a new device named multielectrode cylindrical plasma reactor was presented, where the outer electrode was divided into several strips connected in parallel. The comparative electrical analysis was performed between the multielectrode plasma reactor and the traditional device. The experimental results showed that the multielectrode plasma reactor could give a much lower capacitive current peak value, namely, 5.49 mA compared with 16.26 mA of the traditional one, indicating that the new plasma reactor could decrease the capacitive current to a large extent as designed. In addition, due to the enhanced corona discharge, both the lifetime and peak values of the generated microdischarges were distributed more uniformly and concentrated in a small scale. In addition, the consumed energy by the designed multielectrode plasma reactor was decreased by 29.51% of the traditional plasma reactor, namely, 11.58 W compared with 16.43 W. The discharge mode was analyzed and determined to be mainly filament discharge with enhanced corona discharge at the electrode edges. In conclusion, the plasma reactor with proposed design can give a decreased capacitive current and also the consumed energy, which is helpful in broadening the application field of DBD in plasma catalysis fields.
入藏号: WOS:000455455900042
ISSN: 0093-3813
eISSN: 1939-9375
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第 338 条,共 344 条
标题: Reconstructing a scattered image via spatial cross-phase modulation instability in partially incoherent beams
作者: Han, J (Han, Jing); Liu, HJ (Liu, Hongjun); Huang, N (Huang, Nan); Wang, ZL (Wang, Zhaolu); Zhang, YB (Zhang, Yongbin); Chi, J (Chi, Jiao)
来源出版物: APPLIED PHYSICS EXPRESS 卷: 12 期: 1 文献号: 012007 DOI: 10.7567/1882-0786/aaf713 出版年: JAN 1 2019
摘要: A technology of stochastic resonance is proposed for reconstructing a scattered image, which is based on the spatial cross-phase modulation instability between partially incoherent beams. An original model is built to describe the nonlinear coupling, in which the energy directionally transfers from the background noise to the weak signal. Through reasonably controlling the noise statistics and coupling strength in a nonlinear medium, the profile and details of the underlying image dominated by the scattering noise are efficiently recovered with remarkable cross-correlation gains. This work suggests an efficient method of image detection and holds potential for broader imaging applications in dynamic scattering environments. (C) 2019 The Japan Society of Applied Physics
入藏号: WOS:000455198300003
ISSN: 1882-0778
eISSN: 1882-0786
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第 339 条,共 344 条
标题: Axial resolution enhancement of light-sheet microscopy by double scanning of Bessel beam and its complementary beam
作者: Jia, H (Jia, Hao); Yu, XH (Yu, Xianghua); Yang, YL (Yang, Yanlong); Zhou, X (Zhou, Xing); Yan, SH (Yan, Shaohui); Liu, C (Liu, Chao); Lei, M (Lei, Ming); Yao, BL (Yao, Baoli)
来源出版物: JOURNAL OF BIOPHOTONICS 卷: 12 期: 1 文献号: UNSP e201800094 DOI: 10.1002/jbio.201800094 出版年: JAN 2019
摘要: The side lobes of Bessel beam will create significant out-of-focus background when scanned in light-sheet fluorescence microscopy (LSFM), limiting the axial resolution of the imaging system. Here, we propose to overcome this issue by scanning the sample twice with zeroth-order Bessel beam and another type of propagation-invariant beam, complementary to the zeroth-order Bessel beam, which greatly reduces the out-of-focus background created in the first scan. The axial resolution can be improved from 1.68 mu m of the Bessel light-sheet to 1.07 mu m by subtraction of the two scanned images across a whole field-of-view of up to 300 mu m x 200 mu m x 200 mu m. The optimization procedure to create the complementary beam is described in detail and it is experimentally generated with a spatial light modulator. The imaging performance is validated experimentally with fluorescent beads as well as eGFP-labeled mouse brain neurons.
入藏号: WOS:000455115500018
PubMed ID: 30043551
作者识别号:
作者        Web of Science ResearcherID        ORCID 号
Jia, Hao                  0000-0002-6937-7012
Yu, Xianghua                  0000-0002-7447-1396

ISSN: 1864-063X
eISSN: 1864-0648
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第 340 条,共 344 条
标题: Polarization-based plug-and-play measurement-device-independent quantum key distribution
作者: Hu, M (Hu, Min); Zhang, LT (Zhang, Litao); Guo, BH (Guo, Banghong); Li, J (Li, Jun)
来源出版物: OPTICAL AND QUANTUM ELECTRONICS 卷: 51 期: 1 文献号: 22 DOI: 10.1007/s11082-018-1736-1 出版年: JAN 2019
摘要: Measurement-device-independent quantum key distribution (MDI-QKD) has received much attention, with the goal of overcoming all of the security loopholes caused by an imperfect detection system. We here propose a plug-and-play MDI-QKD (P&P MDI-QKD) scheme whereby an untrusted relay node, Charlie, owns a laser and sends photons to Alice and Bob. Alice (Bob) modulates the polarization of the incident photons and returns them to Charlie. Charlie uses a modified Bell state analyzer (BSA) to perform Bell state measurements (BSM). In comparison with the original version of MDI-QKD, our scheme exploits a single untrusted laser as the photon source. This makes the signal photons identical and enhances the Hong-Ou-Mandel effect. Second, because of the P&P structure, the setup can automatically eliminate the birefringence influence of the fibers, which makes the setup highly stable. Finally, our modified BSA can identify vertical bar phi >+ and vertical bar phi >- of four Bell states with polarization encoding but not vertical bar psi >+ and vertical bar psi >-. Based on practical experimental parameters, a simulation showed that the maximum theoretical secure transmission distance could reach more 280 km.
入藏号: WOS:000454892700003
ISSN: 0306-8919
eISSN: 1572-817X
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第 341 条,共 344 条
标题: On-chip polarization beam splitter with multimode operation in a SOI waveguide
作者: Ge, ZQ (Ge, Zhiqiang); Li, XY (Li, Xingyi); Li, SQ (Li, Siqi); Liu, ML (Liu, Mulong); Si, JH (Si, Jinhai); Zhang, LX (Zhang, Lingxuan)
来源出版物: JAPANESE JOURNAL OF APPLIED PHYSICS 卷: 58 期: 1 文献号: 010905 DOI: 10.7567/1347-4065/aaef92 出版年: JAN 2019
摘要: The polarization beam splitter (PBS) based on the directional coupler is numerically investigated to operate transverse-electric (TE) and transverse-magnetic (TM) modes including high-order modes. Based on the phase-matching condition, all TM-polarization modes are switched from the bus waveguide to the adjacent waveguide without changing the spatial profile of the electric field and mode order while all TE-polarization modes go along the bus waveguide without significant coupling. The results show a low cross talk characteristic (>20 dB at 1.55 mu m) and big fabrication tolerance (delta w = +/- 20 nm). It becomes an essential supplement for polarization splitting with multimode operation in photonics integrated circuits. (C) 2018 The Japan Society of Applied Physics
入藏号: WOS:000453032500002
ISSN: 0021-4922
eISSN: 1347-4065
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第 342 条,共 344 条
标题: Adaptive-window angular spectrum algorithm for near-field ptychography
作者: Pan, A (Pan, An); Zhou, ML (Zhou, Meiling); Zhang, Y (Zhang, Yan); Min, JW (Min, Junwei); Lei, M (Lei, Ming); Yao, BL (Yao, Baolai)
来源出版物: OPTICS COMMUNICATIONS 卷: 430 页: 73-82 DOI: 10.1016/j.optcom.2018.08.035 出版年: JAN 1 2019
摘要: Near-field ptychography provides advantages over far-field ptychography that large field-of-view (FOV) can be imaged with fewer diffraction images, and with weaker requirements on the detector dynamic range and beam coherence, which has drawn attention recently. However, the propagation distance of traditional angular spectrum (AS) method is limited and the reconstruction of the smallest resolvable object detail is restricted by the sensor's pixel size. To this end, we propose an adaptive-window angular spectrum (AWAS) algorithm to solve both problems by adding the window adaptively associated with the propagation distance and avoid the extra computations via extra scaling factors. Meanwhile, it features validity for the independent sample size and the sample number on the observation plane. This algorithm is strictly deduced from the Rayleigh-Sommerfeld formula and based on the linear convolution, which can be evaluated by fast Fourier transform effectively. The burden of calculations is comparable to traditional AS method. The performance has been achieved both in two-dimensional and three-dimensional near-field ptychography with simulations and experiments. This method will make near-field ptychography more practical and can be used in X-ray or electron-microscopy and other computational imaging techniques.
入藏号: WOS:000446073900010
ISSN: 0030-4018
eISSN: 1873-0310
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第 343 条,共 344 条
标题: Polarization properties of calibration reflector system in the polarization-modulated space laser communication
作者: Chen, GQ (Chen, Guoqing); Xue, B (Xue, Bin); Yang, JF (Yang, Jianfeng); Zhao, YY (Zhao, Yiyi); Wang, XF (Wang, Xingfeng); He, JW (He, Jiawei)
来源出版物: OPTICS COMMUNICATIONS 卷: 430 页: 311-317 DOI: 10.1016/j.optcom.2018.06.058 出版年: JAN 1 2019
摘要: S-polarization light and p-polarization light are mutually cross orthogonal, which can be used as signal light for emitting and receiving in the polarization-modulated space laser communication, respectively. Due to the retro reflection characteristics of the corner cube retroreflector (CCR), it is widely used as a calibration reflector system in the polarization-modulated space laser communication. The polarization states of the incident light will be change owing to the total internal reflection (TIR) of uncoated rear surface, in addition, each of the six propagation trips will in general produce a different output polarization. For the calibration reflector system in the polarization-modulated space laser communication, the polarization state of the received light, especially the intensity ratio of the p-polarization component, needs to be clarified. In this paper, a framework is presented to calculate polarization by ray tracing through CCR with arbitrary input polarization states and incident angles. On this basis, the relationships between intensity ratio of the p-polarization component in the received light of each propagation trip and the incident light with different polarization states at normal incidence as well as the circular polarized light at incident angles within +/- 15 degrees analyzed. Theoretical analysis and experiments have guiding significance for the development of the polarization-modulated space laser communication.
入藏号: WOS:000446073900043
ISSN: 0030-4018
eISSN: 1873-0310
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第 344 条,共 344 条
标题: Ultra-thin carbon fiber mirrors: nickel plated, optical fabrication and thermal deformation test
作者: Xu, L (Xu, Liang); Xie, YJ (Xie, Yongjie); Wang, YJ (Wang, Yongjie); Ding, JT (Ding, Jiaoteng); Ma, Z (Ma, Zhen); Fan, XW (Fan, Xuewu)
来源出版物: OPTIK 卷: 176 页: 85-92 DOI: 10.1016/j.ijleo.2018.09.086 出版年: 2019
摘要: The aperture of space remote sensing camera is increasing, and the demand for lighter weight is getting higher and higher. With the advancement of active optics, the thickness of optical components has gradually grown to light and thin. It is extremely difficult to develop ultrathin mirrors using brittle materials such as traditional optical glass and silicon carbide. Due to advantages such as low density, high specific stiffness, low thermal expansion coefficient, toughness, and additive rapid manufacturing properties, carbon fiber reinforced plastic (CFRP) is one of potential applications for large-diameter ultra-thin mirrors. However, the carbon fiber composite material is a two-phase material that cannot be used as optical surface and must be surface-modified. In this paper, the surface modification of CFRP substrate was carried out by chemical nickel plating and nickel electroplating. The modified nickel layer covers all surfaces of CFRP substrate, and nickel layers satisfying the thickness, bonding force, and internal stress requirements. A Phi 100 mm aperture ultra-thin carbon fiber mirror developed, after optical fabricating, its surface accuracy RMS is better than lambda/15. Thermal deformation analysis and test show that the thermal deformation of ultra-thin carbon fiber mirrors is mainly manifested by the change of radius of curvature, which is caused by the thickness error of the nickel layer on the front and rear faces. In addition, although thermal deformation caused by the lamination angle error of CFRP substrate is relatively small in value, it should still be given enough attention, because the astigmatic error produced is hard to eliminate.
入藏号: WOS:000450136500011
ISSN: 0030-4026


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