Record 1 of 358

Title: Strip waveguides in Yb<SUP>3+</SUP>-doped silicate glass formed by combination of He<SUP>+</SUP> ion implantation and precise ultrashort pulse laser ablation

Author(s): Bai, J (Bai, Jing); Wang, J (Wang, Jin); Li, J (Li, Ji); Long, XW (Long, Xue-Wen); Liu, CX (Liu, Chun-Xiao); Xie, P (Xie, Peng); Wang, WQ (Wang, Wei-Qiang)

Source: OPEN PHYSICS  Volume: 20  Issue: 1  Pages: 1295-1302  DOI: 10.1515/phys-2022-0220  Published: DEC 31 2022  

Abstract: Strip optical waveguides were realized in Yb3+-doped silicate glass with ultrashort pulse laser ablation assisted He+ ion implantation. Planar waveguides were first prepared near the glass surface by He+ ion implantation (450 keV + 500 keV + 550 keV), followed by annealing at 260celcius. After that, under the processing parameters of 3 mu J energy and 50 mu m/s ablation velocity, two parallel tracks with separation of 15, 20, and 25 mu m were, respectively, inscribed on the sample, which confine the light in lateral direction to form a strip waveguide. The near-field intensity measurement indicates that the strip waveguides maintain the single-mode propagation characteristics with 976 nm laser injection, and present the multi-mode characteristics with 632.8 nm laser injection, showing that the guided modes are well supported in the strip waveguides. The minimum propagation loss of strip waveguide is 1.35 dB/cm. Fluorescence emission spectra indicate that the gain properties of waveguide core were maintained well after waveguide preparation, revealing that the strip waveguide device in Yb3+-doped silicate glass has the potential to become an active device as waveguide laser or waveguide amplifier.

Accession Number: WOS:000909523000001

ISSN: 2391-5471

Record 2 of 358

Title: Adaptive Style Modulation for Artistic Style Transfer

Author(s): Zhang, YP (Zhang, Yipeng); Hu, BL (Hu, Bingliang); Huang, YY (Huang, Yingying); Gao, C (Gao, Chi); Wang, Q (Wang, Quan)

Source: NEURAL PROCESSING LETTERS  Volume: 55  Issue: 5  Special Issue: SI  Pages: 6213-6230  DOI: 10.1007/s11063-022-11135-7  Early Access Date: DEC 2022   Published: OCT 2023  

Abstract: Arbitrary-style-per-model (ASPM) style transfer algorithms transfer arbitrary styles based on a single model. Statistics-based learning algorithms of ASPM, represented by adaptive instance normalization (AdaIN), conduct instance normalization and then perform an affine transformation on target features. These algorithms are computationally efficient and easy to embed in convolutional neural networks. Consequently, they are widely used in image synthesis tasks to control the style of the resulting images. However, the style of stylized images may be a combination of content and stylized images, which suggests that these methods do not transform styles accurately. In this work, we rethink the function of AdaIN in controlling style. We show that the role of AdaIN is to (1) give each input content image a specific optimization target, (2) dynamically set cross-channel correlations, and (3) act as a feature selector after combining it with an activation function. Accordingly, we propose adaptive style modulation (AdaSM), which fully leverages the three roles mentioned above and thereby enables more precise control of global style. Experimental results show that AdaSM provides superior style controllability, alleviates the style blending problem, and outperforms state-of-the-art methods in artistic style transfer tasks.

Accession Number: WOS:000906095200001

ISSN: 1370-4621

eISSN: 1573-773X

Record 3 of 358

Title: Multiple airy beams light-sheet fluorescence microscopy

Author(s): Gu, SY (Gu, Shuangyu); Yu, XH (Yu, Xianghua); Bai, C (Bai, Chen); Min, JW (Min, Junwei); Li, RZ (Li, Runze); Yang, YL (Yang, Yanlong); Yao, BL (Yao, Baoli)

Source: FRONTIERS IN PHYSICS  Volume: 10  Article Number: 1111023  DOI: 10.3389/fphy.2022.1111023  Published: DEC 23 2022  

Abstract: Light-sheet fluorescence microscopy (LSFM) is a kind of volumetric imaging methodology suited for long term living specimens at high temporal-spatial resolution. A single Airy beam (SAB) light-sheet can extend the field of view of Light-sheet fluorescence microscopy benefiting from its non-diffracting nature, but at the cost of out-of-focus background and low imaging contrast caused by side lobes illumination. Here, we propose a method to generate a sort of multiple Airy beams (MAB), which are linearly superimposed of multiple single Airy beams with different scale factors. Compared to the SAB light-sheet, the energy of the multiple Airy beams light-sheet is more concentrated on the focal plane of the detection objective, which can improve the imaging contrast and decrease the photodamage effect. Furthermore, we combined the complementary beam subtraction (CBS) strategy to increase the axial resolution, termed as multiple Airy beams-complementary beam subtraction method, which enables the axial resolution of 1.2 mu m while keeping the field of view of 450 mu m x 450 mu m. The effectiveness of the method is demonstrated by imaging of fluorescent beads and aspergillus conidiophores.

Accession Number: WOS:000908428100001

Author Identifiers:

ISSN: 2296-424X

Record 4 of 358

Title: Cascaded transfer of optical frequency with a relay station over a 224 km deployed fiber link

Author(s): Zang, Q (Zang, Qi); Deng, X (Deng, Xue); Zhang, X (Zhang, Xiang); Wang, D (Wang, Dan); Zhou, Q (Zhou, Qian); Jiao, DD (Jiao, Dongdong); Xu, GJ (Xu, Guanjun); Gao, J (Gao, Jing); Liu, J (Liu, Jie); Liu, T (Liu, Tao); Dong, RF (Dong, Ruifang); Zhang, SG (Zhang, Shougang)

Source: INFRARED PHYSICS & TECHNOLOGY  Volume: 128  Article Number: 104511  DOI: 10.1016/j.infrared.2022.104511  Early Access Date: DEC 2022   Published: JAN 2023  

Abstract: In this paper, we demonstrate a cascaded transfer of optical frequency with a relay station over a fiber link. The station is outfitted to cascade numerous lines with independent phase locking and provide high optical gain. The relay station receives the signal from the former link and compensates for the power loss with a two-stage EDFA (erbium-doped fiber amplification), and seeds the amplified signal into the next fiber link. By actively suppressing the parasitic noise with a two-stage EDFA, low-noise optical amplification with 50 dB gain is achieved. The two-stage EDFA's simple phase-locking structure also guarantees the system's long-term stability and reliable operation. With this relay station, we transfer a laser frequency along with a 224 km deployed fiber link, and the frequency at the remote end achieves a fractional instability of 3.39 x 10-16 at 1 s averaging time on a 2 Hz measurement bandwidth, reaching 8.36 x 10-19 at 10,000 s. This work paves a way for the future fiber optical frequency transfer network across the nationwide area and it has the potential to be an important part of the cascaded transfer network.

Accession Number: WOS:000912098100001

Author Identifiers:

ISSN: 1350-4495

eISSN: 1879-0275

Record 5 of 358

Title: One-dimensional simulation of Ar dielectric barrier discharge driven by combined rf/dc sources at atmospheric pressure

Author(s): Qi, B (Qi Bing); Tian, X (Tian Xiao); Wang, J (Wang Jing); Wang, YS (Wang Yi-Shan); Si, JH (Si Jin-Hai); Tang, J (Tang Jie)

Source: ACTA PHYSICA SINICA  Volume: 71  Issue: 24  Article Number: 245202  DOI: 10.7498/aps.71.20221361  Published: DEC 20 2022  

Abstract: We present the dielectric barrier discharge (DBD) mechanism of argon (Ar) plasma driven by a combination of radio frequency (rf) voltage source and direct current (dc) voltage source at atmospheric pressure, based on one-dimensional self-consistent coupled fluid model. Using the finite element method (FEM) to numerically calculate the model, the average value of period average electron density varying with the average value of period average gas voltage in one rf period, and the variation of the minimum rf sustaining voltage are obtained under different dc voltages. In addition, the spatiotemporal distribution of the electron density and electron generation rate, the spatial distribution of electron temperature, and the time-domain variation of electron conduction current flowing to the dielectric are studied. The results show that the introduction of the dc voltage source has a significant effect on the rf discharge process of atmospheric pressure Ar gas, and the parameters of the plasma state are changed correspondingly. The discharge process is mainly controlled by the air gap voltage, and the dc voltage affects the gap voltage by changing the charge density on the dielectric surface. The minimum rf sustaining voltage Vrf, min first increases and then decreases with the increase of dc voltage. The amplitude of rf minimum sustaining discharge voltage is changed by the dc voltage. And when the amplitude is reached or exceeded, the discharge is controlled by the rf power supply.
On the one hand, in the a mode, when the dc voltage is low, electrons are generated near the ground electrode. The electric field intensity in the ionization area is too small to maintain ionization. When the dc voltage is high, the sheath is formed, and electrons are generated near the rf sheaths on both sides and the boundary of the plasma region. In the g mode, when the rf voltage amplitude is equal to or greater than the rf minimum sustain discharge voltage amplitude, i.e. Vrf = Vrf,min, the generation and distribution of electrons are almost unaffected by the dc voltage.
On the other hand, in the a mode, the ionization cannot be sustained for the low dc voltage, resulting in the failure to form the main plasma area. Therefore, the electron temperature is generally high. Owing to the high electron density near the ground electrode, the electron temperature is higher. The electron density near the dielectric is less than that near the electrode, so the temperature is lower. When the dc voltage is getting larger, the sheath and the main plasma region are formed. The dc voltage significantly affects the electron temperature by controlling the sheath voltage and the length of the main plasma region.
Finally, in the a mode, the electron density near the medium is very low and the air gap voltage is negative for the low dc voltage. As a result, few electrons can reach the surface of the dielectric, and the conduction current of electrons flowing to the medium is very small. With the increase of the dc voltage, the electric field across air gap increases, and electrons, under the action of the electric field, flow from the dielectric surface. The sheath having formed, some speedy non-localization electrons that have reached the dielectric surface are reflected back to the sheath, resulting in a significant reduction in the number of electrons that can reach the dielectric surface.

Accession Number: WOS:000970023300026

ISSN: 1000-3290

Record 6 of 358

Title: Push-broom compressive hyperspectral imaging method based on self-fusion refinement

Author(s): Zhu, MJ (Zhu, Mengjun); Yi, WJ (Yi, Wenjun); Du, JY (Du, Junyi); Zhu, SY (Zhu, Shuyue); Qi, JL (Qi, Junli); Fu, MC (Fu, Meicheng); Li, LB (Li, Libo); Li, XJ (Li, Xiujian)

Source: OPTICS COMMUNICATIONS  Volume: 530  Article Number: 129198  DOI: 10.1016/j.optcom.2022.129198  Early Access Date: DEC 2022   Published: MAR 1 2023  

Abstract: Compressive hyperspectral imaging (CHI) with random encoding mask usually suffers from various noises and artifacts. Inspired by the dual-camera CHI techniques based on hyperspectral (HS) and multispectral (MS) image fusion, herein, we present a single-camera push-broom CHI method based on self-fusion refinement (SFR). In this work, the MS guidance image for data fusion is derived directly from the raw solved HS data cube itself rather than any additional data source, which turns cross-fusion into self-fusion; furthermore, a modified joint bilateral filtering (JBF) fusion algorithm is developed to adapt this self-fusion problem, and an adaptive range Gaussian radius is adopted to avoid the invalidation or over-smoothing effects so as to ensure spatial and spectral improvement. The visualized and quantitative assessment results both demonstrate that the proposed method achieves high-quality HS imaging in terms of noise and artifact removal and spatial-spectral fidelity. Furthermore, the proposed method has a great flexibility and extensibility, whose performances highly depend on the exact fusion algorithm adopted, and a more suitable fusion algorithm will lead to better reconstruction quality; herein, the SFR process by the modified JBF achieves better performances than SFR by guided filtering (GF) or Markov random field (MRF).

Accession Number: WOS:000912408000001

Author Identifiers:

ISSN: 0030-4018

eISSN: 1873-0310

Record 7 of 358

Title: Image blurring and spectral drift in imaging spectrometer system with an acousto-optic tunable filter and its application in UAV remote sensing

Author(s): Liu, H (Liu, Hong); Hou, XS (Hou, Xingsong); Hu, BL (Hu, Bingliang); Yu, T (Yu, Tao); Zhang, ZF (Zhang, Zhoufeng); Liu, X (Liu, Xiao); Liu, JC (Liu, Jiacheng); Wang, XJ (Wang, Xueji); Zhong, JJ (Zhong, Jingjing); Tan, ZX (Tan, Zhengxuan)

Source: INTERNATIONAL JOURNAL OF REMOTE SENSING  Volume: 43  Issue: 19-24  Pages: 6957-6978  DOI: 10.1080/01431161.2022.2150395  Published: DEC 17 2022  

Abstract: In the design and research of an unmanned aerial vehicle-borne hyperspectral imager with an acousto-optic tunable filter (AOTF), the depth of the field range of the imaging objective lens is fixed, the spectral range of 400-1000nm is wide, and the AOTF crystal has different deflection angles for diffracted light of different wavelengths. These features all cause problems such as image blurring and spectral drifts. Therefore, we propose a solution using a tunable zoom lens and multi-modal spectrum registration to solve these problems. We also propose an improved image definition evaluation function using the zoom lens to obtain clear horizontal lines and blurred vertical lines and, thereby, hope to overcome image blurring in an AOTF spectrometer. The zoom parameters corresponding to the clear image in each spectral segment of the AOTF spectrometer can be determined rapidly and accurately. However, it is difficult to establish a mathematical model of the drift, using wavelength as a variable, to compensate the drift due to the clear image of each spectrum obtained using the zoom lens. The calibration method completes the registration of the spectral data cube composed of clear images, solving the problem of spectral band drift. Moreover, it has been verified through UAV-borne hyperspectral imaging that image blurring and spectral drift of the AOTF imaging spectrometer were significantly reduced, providing opportunities for the application and research of AOTF-based hyperspectral imagers in more fields, such as remote sensing.

Accession Number: WOS:000899436400001

Author Identifiers:

ISSN: 0143-1161

eISSN: 1366-5901

Record 8 of 358

Title: Polarization-multiplexed dual-comb fiber laser based on an all-polarization-maintaining cavity configuration

Author(s): Rao, BJ (Rao, Bingjie); Li, MK (Li, Mingkun); Yang, XG (Yang, Xiguang); Yan, LL (Yan, Lulu); Chen, X (Chen, Xin); Yuan, R (Yuan, Ru); Zhang, P (Zhang, Pan); Zhang, SG (Zhang, Shougang)

Source: FRONTIERS IN PHYSICS  Volume: 10  Article Number: 1073201  DOI: 10.3389/fphy.2022.1073201  Published: DEC 16 2022  

Abstract: In this study, we present a polarization-multiplexed, erbium-doped dual-comb fiber laser based on an all-polarization-maintaining cavity configuration. We observed that the dual-comb fiber laser easily realized the self-starting mode-locking operation due to the non-linear amplifying loop mirror (NALM) with a non-reciprocal phase shifter. Furthermore, owing to the sharing of the NALM part, the two outputs from this laser configuration had similar center wavelengths, with small different repetition rates ( increment f (rep)). In the free-running operation, the standard deviation of relative stability for & UDelta;f (rep) of 2.09 kHz was measured to be 1.59 Hz, and the full width at half-maximum of the relative beat note between the two frequency combs in the optical frequency domain was approximately 1 kHz. These results show that the two frequency combs from this laser configuration have high relative stability and mutual coherence.

Accession Number: WOS:000905504700001

Author Identifiers:

ISSN: 2296-424X

Record 9 of 358

Title: Surface generation mechanism of the rotary ultrasonic vibration-assisted grinding of aspheric glass ceramics

Author(s): Sun, GY (Sun, Guoyan); Shi, F (Shi, Feng); Zhang, BW (Zhang, Bowen); Zhao, QL (Zhao, Qingliang); Zhang, WL (Zhang, Wanli); Wang, YJ (Wang, Yongjie); Tian, Y (Tian, Ye)

Source: INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY  Volume: 124  Issue: 7-8  Pages: 2579-2595  DOI: 10.1007/s00170-022-10532-5  Early Access Date: DEC 2022   Published: FEB 2023  

Abstract: A serious challenge faced by manufacturers of large-aperture aspheric optical components of glass ceramics is the long processing time. Ultrasonic vibration-assisted grinding (UVG) allows one to effectively shorten the subsequent polishing process by several times, which is essential for grinding of aspheric components. However, the surface creation mechanism of UVG-treated glass ceramics is rarely studied. Herein, rotary ultrasonic vibration-assisted vertical grinding (RUVG) and parallel grinding (RUPG) are applied to polish the aspheric glass ceramics. Particular attention is paid to the surface formation mechanism of UVG-processed ceramics. The single-grain kinematic functions are created and the contact characteristics between the grinding wheel and aspheric surface are analyzed for the two UVG methods in terms of contact area, velocity, and trajectory. In addition, aspheric grinding texture is simulated and comparative experiments are conducted correspondingly. According to the results, the rotary ultrasonic vibration mainly influences the microscopic grinding marks. Besides, the aspheric surface form accuracy of Pt and RMS value in RUVG is 2.16 and 3.71 times lower than those in RUPG, respectively, whereas the surface roughness-related parameters (mean deviation Sa and maximum height of profile Sz) in RUVG are 6.36% and 4.56% higher than those in RUPG. This indicates that RUVG is more suitable for high precision and efficiency grinding of the aspheric surface than RUPG due to the fact that the polishing depth is primarily determined by surface form accuracy rather than surface roughness. Thus, the current research enables an in-depth understanding of surface generation mechanism in rotary ultrasonic vibration-assisted grinding, pointing out its benefits in the high-efficiency aspheric surface manufacturing.

Accession Number: WOS:000899462700003

Author Identifiers:

ISSN: 0268-3768

eISSN: 1433-3015

Record 10 of 358

Title: High-precision gaseous flame temperature field measurement based on quadriwave-lateral shearing interferometry

Author(s): Yuan, X (Yuan, Xun); Xue, YG (Xue, Yuge); Min, JW (Min, Junwe); Yu, XH (Yu, Xianghua); Li, MM (Li, Manman); Li, RZ (Li, Runze); Yao, BL (Yao, Baoli)

Source: OPTICS AND LASERS IN ENGINEERING  Volume: 162  Article Number: 107430  DOI: 10.1016/j.optlaseng.2022.107430  Early Access Date: DEC 2022   Published: MAR 2023  

Abstract: Quadriwave-lateral shearing interferometry (QLSI) has a broad utilization in quantitative phase imaging (QPI) for refraction-type objects due to its compact structure and stable performance against external disturbance. Here we propose to use the QLSI technique to image and measure the gaseous flame temperature field distribution in high precision. The quantitative phase image of an axisymmetric candle flame is firstly reconstructed from the wire-mesh-like QLSI interferogram, and then the three-dimensional temperature field distribution is calcu-lated with the axisymmetric projection transform algorithm. Compared to the conventional digital holographic interferometry (DHI) based on Mach-Zehnder architecture, the proposed method possesses a high-precision mea-surement and better stability in disturbed environment, benefiting from the compact common-path structure of QLSI. The temperature measurement errors of the proposed QLSI method are +/- 5.0 K and +/- 5.3 K in the presence of airflow disturbance and mechanical vibration, respectively, while those of the DHI method are +/- 7.6 K and +/- 12.9 K, respectively.

Accession Number: WOS:000906687600001

Author Identifiers:

ISSN: 0143-8166

eISSN: 1873-0302

Record 11 of 358

Title: Modeling and analysis of fast steering mirror disturbance effects on the line of sight jitter for precision pointing and tracking system

Author(s): Lv, T (Lv, Tao); Ruan, P (Ruan, Ping); Jiang, K (Jiang, Kai); Jing, F (Jing, Feng)

Source: MECHANICAL SYSTEMS AND SIGNAL PROCESSING  Volume: 188  Article Number: 110002  DOI: 10.1016/j.ymssp.2022.110002  Early Access Date: DEC 2022   Published: APR 1 2023  

Abstract: Fast steering mirrors (FSMs) are typically applied for beam stabilization for precision pointing and tracking systems (PPTSs) owing to their high-bandwidth, high-resolution, and high accu-racy. In addition to the advantages, the presence of the residual momentum which caused by FSMs' operation usually has noticeable effects on the stabilization of the line of sight (LOS) for PPTSs. Hence, it is necessary and momentous to estimate the effects of these disturbances to give insight into the FSM specification and the PPTS structural performance. However, the characteristic of multidisciplinary coupling makes it a challenge to measure the LOS jitter caused by FSMs. We approach this problem by establishing an integrated model for estimating the LOS jitter. A dynamic model of an FSM is firstly built to value the unbalanced momentum generated from its motion. Then a finite element model for the structure of the tracking system is established to predict the dynamic response excited by the disturbances from the FSM. In addition, with a linear optical model, the system optical performance under the FSM's disturbances is determined. Finally, a test is conducted to verify the validity of the model and the analysis. This paper focuses on estimating the disturbances effects of the FSM on the LOS jitter for a PPTS, and providing potential approaches for reducing these effects.

Accession Number: WOS:000994343100001

Author Identifiers:

ISSN: 0888-3270

eISSN: 1096-1216

Record 12 of 358

Title: Velocity history measurement of hypersonic tunnel driver based on photon Doppler velocimeter

Author(s): Hao, GY (Hao Ge-Yang); Yang, YC (Yang Yu-Cheng); Zhao, RJ (Zhao Rong-Juan); Lü, XP (Lu Xiao-Peng); Yang, YH (Yang Ya-Han); Wu, GJ (Wu Guo-Jun)

Source: ACTA PHYSICA SINICA  Volume: 71  Issue: 23  Article Number: 234208  DOI: 10.7498/aps.71.20221234  Published: DEC 5 2022  

Abstract: The research of hypersonic process is limited by the transition model, the turbulence model, and the computational complexity. At present the tunnel test is still a better way to investigate the hypersonic process than the computational fluid dynamic (CFD) method. In this work, the principle and structure of all-fiber photon Doppler velocimeter (PDV) are introduced. The PDV is based on laser Doppler effect and consists of an all-fiber Mach Zehnder interferometer and an optical antenna. The measurement accuracy and distance of PDV are tested, showing that the error can be controlled to be within 0.17 m/s when the velocity of piston is below 40 m/s. At the same time, the measured distance of PDV can reach 26.3 m. The continuous velocity of the free piston is measured by using the PDV in high enthalpy expansion tunnel of China aerodynamics research and development center (CARDC). During the tunnel tests, the PDV is placed next to the tunnel, and the optical antenna is installed behind the observation window of the tunnel and connected to a circulator by optical fiber. When the driving pressure of the tunnel is 1.3 MPa, the maximum numerical simulation velocity of the piston is 88.981 m/s, and the velocity is measured to be 88.810 m/s with a relative deviation of -0.19%; when the driving pressure of the tunnel is 2.7 MPa, the maximum numerical simulation velocity of the piston is 125.100 m/s, the measured velocity is 123.843 m/s, and the relative deviation is -1.00%. The piston reaches a maximum velocity before impacting on the tunnel, and then decelerates rapidly under the joint action of the driving pressure and compression wave. Therefore, the soft landing of the piston proves feasible, which is put forward by Stallkerin the 1960s. Finally, the reasons why PDV missed the impact velocity of piston is discussed. Through the analysis of received intensity, it is believed that the absorption, scattering and expansion of the laser beam caused by the strong driving pressure is the main reason.

Accession Number: WOS:000898652500010

Author Identifiers:

ISSN: 1000-3290

Record 13 of 358

Title: A Single-Celled Metasurface for Multipolarization Generation and Wavefront Manipulation

Author(s): Ji, RA (Ji, Ruonan); Guo, X (Guo, Xin); Liu, ZC (Liu, Zhichao); Wu, XF (Wu, Xianfeng); Jin, C (Jin, Chuan); Liu, F (Liu, Feng); Zheng, XR (Zheng, Xinru); Sun, Y (Sun, Yang); Wang, SW (Wang, Shaowei)

Source: NANOMATERIALS  Volume: 12  Issue: 23  Article Number: 4336  DOI: 10.3390/nano12234336  Published: DEC 2022  

Abstract: Due to their unprecedented ability to flexibly manipulate the parameters of light, metasurfaces offer a new approach to integrating multiple functions in a single optical element. In this paper, based on a single-celled metasurface composed of chiral umbrella-shaped metal-insulator-metal (MIM) unit cells, a strategy for simultaneous multiple polarization generation and wavefront shaping is proposed. The unit cells can function as broadband and high-performance polarization-preserving mirrors. In addition, by introducing a chiral-assisted Aharonov-Anandan (AA) geometric phase, the phase profile and phase retardation of two spin-flipped orthogonal circular polarized components can be realized simultaneously and independently with a single-celled metasurface via two irrelevant parameters. Benefiting from this flexible phase manipulation ability, a vectorial hologram generator and metalens array with spatially varying polarizations were demonstrated. This work provides an effective approach to avoid the pixel and efficiency losses caused by the intrinsic symmetry of the PB geometric phase, and it may play an important role in the miniaturization and integration of multipolarization-involved displays, real-time imaging, and spectroscopy systems.

Accession Number: WOS:000897469500001

PubMed ID: 36500959

Author Identifiers:

eISSN: 2079-4991

Record 14 of 358

Title: Coastline Recognition Algorithm Based on Multi-Feature Network Fusion of Multi-Spectral Remote Sensing Images

Author(s): Qiu, S (Qiu, Shi); Ye, HP (Ye, Huping); Liao, XH (Liao, Xiaohan)

Source: REMOTE SENSING  Volume: 14  Issue: 23  Article Number: 5931  DOI: 10.3390/rs14235931  Published: DEC 2022  

Abstract: Remote sensing images can obtain broad geomorphic features and provide a strong basis for analysis and decision making. As 71% of the earth is covered by water, shipping has become an efficient means of international trade and transportation, and the development level of coastal cities will directly reflect the development level of a country. The coastline is the boundary line between seawater and land, so it is of great significance to accurately identify it to assist shipping traffic and docking, and this identification will also play a certain auxiliary role in environmental analysis. Currently, the main problems of coastline recognition conducted by remote sensing images include: (1) in the process of remote sensing, image transmission inevitably brings noise causing poor image quality and difficult image quality enhancement; (2) s single scale does not allow for the identification of coastlines at different scales; and (3) features are under-utilized, false detection is high and intuitive measurement is difficult. To address these issues, we used the following multispectral methods: (1) a PCA-based image enhancement algorithm was proposed to improve image quality; (2) a dual attention network and HRnet network were proposed to extract suspected coastlines from different levels; and (3) a decision set fusion approach was proposed to transform the coastline identification problem into a probabilistic problem for coastline extraction. Finally, we constructed a coastline straightening model to visualize and analyze the recognition effect. Experiments showed that the algorithm has an AOM greater than 0.88 and can achieve coastline extraction.

Accession Number: WOS:000896459100001

Author Identifiers:

eISSN: 2072-4292

Record 15 of 358

Title: Terabit FSO communication based on a soliton microcomb

Author(s): Shao, W (Shao, Wen); Wang, Y (Wang, Yang); Jia, SW (Jia, Shuaiwei); Xie, Z (Xie, Zhuang); Gao, DR (Gao, Duorui); Wang, W (Wang, Wei); Zhang, DQ (Zhang, Dongquan); Liao, PX (Liao, Peixuan); Little, BE (Little, Brent E.); Chu, ST (Chu, Sai T.); Zhao, W (Zhao, Wei); Zhang, WF (Zhang, Wenfu); Wang, WQ (Wang, Weiqiang); Xie, XP (Xie, Xiaoping)

Source: PHOTONICS RESEARCH  Volume: 10  Issue: 12  Pages: 2802-2808  DOI: 10.1364/PRJ.473559  Published: DEC 1 2022  

Abstract: Free-space optical (FSO) communication technology is a promising approach to establish a secure wireless link, which has the advantages of excellent directionality, large bandwidth, multiple services, low mass and less power requirements, and easy and fast deployments. Increasing the communication capacity is the perennial goal in both scientific and engineer communities. In this paper, we experimentally demonstrate a Tbit/s parallel FSO communication system using a soliton microcomb as a multiple wavelength laser source. Two communication terminals are installed in two buildings with a straight-line distance of similar to 1 km. 102 comb lines are modulated by 10 Gbit/s differential phase-shift keying signals and demodulated using a delay-line interferometer. When the transmitted optical power is amplified to 19.8 dBm, 42 optical channels have optical signal-to-noise ratios higher than 27 dB and bit error rates less than 1 x 10-9. Our experiment shows the feasibility of a wavelength-division multiplexing FSO communication system which suits the ultra-high-speed wireless transmission application scenarios in future satellite-based communications, disaster recovery, defense, last mile problems in networks and remote sensing, and so on. (c) 2022 Chinese Laser Press

Accession Number: WOS:000914456800016

Author Identifiers:

ISSN: 2327-9125

Record 16 of 358

Title: An Integrated Solution of UAV Push-Broom Hyperspectral System Based on Geometric Correction with MSI and Radiation Correction Considering Outdoor Illumination Variation

Author(s): Song, LY (Song, Liyao); Li, HW (Li, Haiwei); Chen, TQ (Chen, Tieqiao); Chen, JY (Chen, Junyu); Liu, S (Liu, Song); Fan, JC (Fan, Jiancun); Wang, Q (Wang, Quan)

Source: REMOTE SENSING  Volume: 14  Issue: 24  Article Number: 6267  DOI: 10.3390/rs14246267  Published: DEC 2022  

Abstract: The unmanned aerial vehicle (UAV)-borne hyperspectral imaging system has the advantages of high spatial resolution, flexible operation, under-cloud flying, and easy cooperation with ground synchronous tests. Because this platform often flies under clouds, variations in solar illumination lead to irradiance inconsistency between different rows of hyperspectral images (HSIs). This inconsistency causes errors in radiation correction. In addition, due to the accuracy limitations of the GPS/inertial measurement unit (IMU) and irregular changes in flight platform speed and attitude, HSIs have deformation and drift, which is harmful to the geometric correction and stitching accuracy between flight strips. Consequently, radiation and geometric error limit further applications of large-scale hyperspectral data. To address the above problems, we proposed an integrated solution to acquire and correct UAV-borne hyperspectral images that consist of illumination data acquisition, radiance and geometric correction, HSI, multispectral image (MSI) registration, and multi-strip stitching. We presented an improved three-parameter empirical model based on the illumination correction factor, and it showed that the accuracy of radiation correction considering illumination variation improved, especially in some low signal-to-noise ratio (SNR) bands. In addition, the error of large-scale HSI stitching was controlled within one pixel.

Accession Number: WOS:000904558200001

Author Identifiers:

eISSN: 2072-4292

Record 17 of 358

Title: Recording and modeling the seasonal growth of salt marsh vegetation at Liao river estuary, China, based on the wetland image monitoring system (WIMS)

Author(s): Wang, YC (Wang, Yicong); Liang, XM (Liang, Xianmeng); Yu, Y (Yu, Yang); Yu, CB (Yu, Changbin); Yang, M (Yang, Min); Wu, GJ (Wu, Guojun)

Source: WETLANDS ECOLOGY AND MANAGEMENT  Volume: 31  Issue: 1  Pages: 1-18  DOI: 10.1007/s11273-022-09897-x  Early Access Date: DEC 2022   Published: FEB 2023  

Abstract: Wetland ecology monitoring is an essential technical guarantee for the protection and restoration of the fragile ecosystem of wetlands. Due to the degradation of keystone species Suaeda HeteropteraPall. (S. Heteroptera) in the Liao River Estuary wetland, the Wetland Image Monitoring System (WIMS) was established to obtain real-time, continuous, high spatiotemporal resolution data about the coverage and height of S. Heteroptera. Based on the monitoring data, we elicited the best model to describe the variation of the coverage and height for S. Heteroptera. The results showed that the growth of S. Heteroptera could be divided into three stages: rapid growth stage (April-May), slow growth stage (June-August), and stable stage (after September). The Bertalanffy model was the best choice for the coverage simulation of S. Heteroptera. The segment model composed of the linear and Gompertz models was suitable for the height simulation of S. Heteroptera, which could effectively reduce the relative error compared with the single model. In addition, the WIMS could potentially capture other important ecological factors in local regions, including benthic animals, birds, waterlogging conditions, etc. Although WIMS has some application limitations, the high spatiotemporal resolution and relatively low cost make it an effective tool to explore the degradation of typical ecosystems under climate change and human activities.

Accession Number: WOS:000912581400001

Author Identifiers:

ISSN: 0923-4861

eISSN: 1572-9834

Record 18 of 358

Title: Modulator-Free Variable Multi-Rate FSO Communication 1 km Outfield Demonstration Based on Chirp-Managed Laser

Author(s): Xie, Z (Xie, Zhuang); Jia, SW (Jia, Shuaiwei); Shao, W (Shao, Wen); Wang, Y (Wang, Yang); Ma, R (Ma, Rong); Wei, ST (Wei, Sentao); Liao, PX (Liao, Peixuan); Zhang, DQ (Zhang, Dongquan); Wang, WQ (Wang, Weiqiang); Gao, DR (Gao, Duorui); Wang, W (Wang, Wei); Xie, XP (Xie, Xiaoping)

Source: IEEE PHOTONICS JOURNAL  Volume: 14  Issue: 6  Article Number: 7956706  DOI: 10.1109/JPHOT.2022.3211268  Published: DEC 2022  

Abstract: Due to the high energy efficiency per bit and high sensitivity, Return-to-zero differential-phase-shift-keying (RZ-DPSK) is perfectly suitable for free-space laser communications. However, the conventional generation method of RZ-DPSK optical signal requires two modulators, which is costly, bulky, and heavy, significantly hindering the application of RZ-DPSK in size, weight, and power (SWaP)-constrained satellite platforms. In this paper, we propose and experimentally demonstrate a modulator-free variable multi-rate RZ-DPSK free-space optical (FSO) communication system based on chirp-managed laser (CML). Based on the proposed scheme, an FSO outfield experiment over 1 km has been successfully undertaken, achieving receiving sensitivities of -48.9 dBm and -45.6 dBm at 2.5 Gbps and 5 Gbps, with bit error rate (BER) of 1 x 10(-3) without forward error correction (FEC), respectively. The performance of the proposed system is also investigated by studying the eye diagrams under two different test conditions of back-to-back transmission and 1-km free space transmission. In addition to the small size, lightweight and low cost, the proposed scheme shows great potential for a variety of FSO communication applications ranging from Cube-Star to larger satellite laser communication platforms.

Accession Number: WOS:000870286800001

Author Identifiers:

ISSN: 1943-0655

eISSN: 1943-0647

Record 19 of 358

Title: Dynamics of frustrated tunneling ionization driven by inhomogeneous laser fields

Author(s): Xu, JK (Xu, Jingkun); Zhou, YM (Zhou, Yueming); Li, YB (Li, Yingbin); Liu, AH (Liu, Aihua); Chen, YK (Chen, Yongkun); Ma, XM (Ma, Xiaomeng); Huang, X (Huang, Xiang); Liu, KL (Liu, Kunlong); Zhang, QB (Zhang, Qingbin); Li, M (Li, Min); Yu, BH (Yu, Benhai); Lu, PX (Lu, Peixiang)

Source: NEW JOURNAL OF PHYSICS  Volume: 24  Issue: 12  Article Number: 123043  DOI: 10.1088/1367-2630/acadfe  Published: DEC 1 2022  

Abstract: We theoretically investigated frustrated tunneling ionization (FTI) driven by spatially inhomogeneous strong laser fields induced by surface plasmon resonance within a bow-tie metal nanostructure. The results show that the FTI probability and the principal quantum number distribution exhibit similar oscillatory behavior as a function of the pulse duration. Our analysis reveals that the periodic defocusing and refocusing of the electron spatial distribution due to the inhomogeneous laser field is responsible for the oscillatory structures. In addition, the initial tunneling coordinates and the angular momentum distributions of the FTI events and theirs pulse duration dependence are also explored. Moreover, our results show that the frequency of the oscillatory structures depends sensitively on the electron quiver amplitude and the inhomogeneity strength. Thus, the electron quiver amplitude and the size of the gap between bow-tie nanostructure are useful and efficient knobs for controlling the yield and properties of exited Rydberg states.

Accession Number: WOS:000906869100001

Author Identifiers:

ISSN: 1367-2630

Record 20 of 358

Title: Design of Passive Constant-Force End-Effector for Robotic Polishing of Optical Reflective Mirrors

Author(s): Zhang, J (Zhang, Jian); Zhao, LX (Zhao, Liangxiao); Li, LL (Li, Lingling); Ma, FL (Ma, Fulei); Chen, GM (Chen, Guimin)

Source: CHINESE JOURNAL OF MECHANICAL ENGINEERING  Volume: 35  Issue: 1  Article Number: 141  DOI: 10.1186/s10033-022-00811-3  Published: DEC 2022  

Abstract: Polishing plays an indispensable role in optical processing, especially for large-aperture optical reflective mirrors with freeform surfaces. Robotic polishing requires effective control of the contact force between the robot and the mirror during processing. In order to maintain a constant contact force during polishing, traditional polishing robots rely on closed-loop control of air cylinders, whose performances heavily rely on high-fidelity force sensing and real-time control. This paper proposes to employ a compliant constant-force mechanism in the end-effector of a polishing robot to passively maintain a constant force between the robot and the mirror, thus eliminating the requirement for force sensing and closed-loop control. The compliant constant force mechanism utilizing the second bending mode of fixed-guided compliant beams is adopted and elaborated for the passive end-effector. An end-effector providing a constant contact force of 40 N is designed and prototyped. The polishing experiment shows that the passive constant-force end-effector provides stable contact force between the robot and the mirror with fluctuation within 3.43 N, and achieves RMS (Root Mean Square) lower than lambda/10 (lambda = 632.8 nm) of the polished surface of the large-aperture optical reflective mirror. It is concluded that the constant-force compliant mechanism provides a low-cost and reliable solution for force control in robotic polishing.

Accession Number: WOS:000888746400001

Author Identifiers:

ISSN: 1000-9345

eISSN: 2192-8258

Record 21 of 358

Title: Classical Analog and Hybrid Metamaterials of Tunable Multiple-Band Electromagnetic Induced Transparency

Author(s): Zhang, Z (Zhang, Zhi); Gao, DR (Gao, Duorui); Si, JH (Si, Jinhai); Meng, JC (Meng, Jiacheng)

Source: NANOMATERIALS  Volume: 12  Issue: 24  Article Number: 4405  DOI: 10.3390/nano12244405  Published: DEC 2022  

Abstract: The electromagnetic induced transparency (EIT) effect originates from the destructive interference in an atomic system, which contributes to the transparency window in its response spectrum. The implementation of EIT requires highly demanding laboratory conditions, which greatly limits its acceptance and application. In this paper, an improved harmonic spring oscillation (HSO) model with four oscillators is proposed as a classical analog for the tunable triple-band EIT effect. A more general HSO model including more oscillators is also given, and the analyses of the power absorption in the HSO model conclude a formula, which is more innovative and useful for the study of the multiple-band EIT effect. To further inspect the analogizing ability of the HSO model, a hybrid unit cell containing an electric dipole and toroidal dipoles in the metamaterials is proposed. The highly comparable transmission spectra based on the HSO model and metamaterials indicate the validity of the classical analog in illustrating the formation process of the multiple-band EIT effect in metamaterials. Hence, the HSO model, as a classical analog, is a valid and powerful theoretical tool that can mimic the multiple-band EIT effect in metamaterials.

Accession Number: WOS:000902957400001

PubMed ID: 36558255

Author Identifiers:

eISSN: 2079-4991

Record 22 of 358

Title: Epitaxially-Stacked High Efficiency Laser Diodes Near 905 nm

Author(s): Zhao, YL (Zhao, Yuliang); Yang, GW (Yang, Guowen); Zhao, YM (Zhao, Yongming); Tang, S (Tang, Song); Lan, Y (Lan, Yu); Liu, YX (Liu, Yuxian); Wang, ZF (Wang, Zhenfu); Demir, A (Demir, Abdullah)

Source: IEEE PHOTONICS JOURNAL  Volume: 14  Issue: 6  Article Number: 1557006  DOI: 10.1109/JPHOT.2022.3211964  Published: DEC 2022  

Abstract: We report on studying tunnel junctions and an optical cavity structure for developing epitaxially-stacked high-efficiency 905 nm high-power laser diodes. The GaAs tunnel junctions were explored via simulations and experiments to realize a high peak current density of 7.7 x 10(4) A/cm(2) and a low specific resistance of 1.5 x 10(-5) omega cm(2) with a high n-doping concentration of 6 x 10(19) cm(-3). Employing a low-loss epitaxial structure design, single-, double-, and triple-cavity structure laser diodes demonstrated power scaling by epitaxial stacking. Triple-cavity laser diodes have a low optical loss (0.42 cm(-1)) and generate a peak power of 83 W with a short cavity length of 750 mu m at a limited current of 30 A.

Accession Number: WOS:000870286800003

Author Identifiers:

ISSN: 1943-0655

eISSN: 1943-0647

Record 23 of 358

Title: Refinement method for compressive hyperspectral data cubes based on self-fusion

Author(s): Zhu, MJ (Zhu, Mengjun); Yi, WJ (Yi, Wenjun); Dong, ZH (Dong, Zhaohua); Xiong, P (Xiong, Peng); Du, JY (DU, Junyi); Tang, XJ (Tang, Xingjia); Yang, Y (Yang, Ying); Li, LB (LI, Libo); Qi, JL (Qi, Junli); Liu, J (Liu, Ju); Li, XJ (LI, Xiujian)

Source: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION  Volume: 39  Issue: 12  Pages: 2282-2290  DOI: 10.1364/JOSAA.465165  Published: DEC 1 2022  

Abstract: Compressive hyperspectral images often suffer from various noises and artifacts, which severely degrade the imag-ing quality and limit subsequent applications. In this paper, we present a refinement method for compressive hyperspectral data cubes based on self-fusion of the raw data cubes, which can effectively reduce various noises and improve the spatial and spectral details of the data cubes. To verify the universality, flexibility, and extensibil-ity of the self-fusion refinement (SFR) method, a series of specific simulations and practical experiments were conducted, and SFR processing was performed through different fusion algorithms. The visual and quantitative assessments of the results demonstrate that, in terms of noise reduction and spatial-spectral detail restoration, the SFR method generally is much better than other typical denoising methods for hyperspectral data cubes. The results also indicate that the denoising effects of SFR greatly depend on the fusion algorithm used, and SFR imple-mented by joint bilateral filtering (JBF) performs better than SRF by guided filtering (GF) or a Markov random field (MRF). The proposed SFR method can significantly improve the quality of a compressive hyperspectral data cube in terms of noise reduction, artifact removal, and spatial and spectral detail improvement, which will further benefit subsequent hyperspectral applications.(c) 2022 Optica Publishing Group

Accession Number: WOS:000893235500001

PubMed ID: 36520747

Author Identifiers:

ISSN: 1084-7529

eISSN: 1520-8532

Record 24 of 358

Title: Modified achromatic Savart polariscope for broadband spatially modulated snapshot imaging polarimeter

Author(s): Quana, NC (Quana, Naicheng); Lia, SY (Lia, Siyuan); Zhang, CM (Zhang, Chunmin)

Source: OPTICS AND LASERS IN ENGINEERING  Volume: 162  Article Number: 107398  DOI: 10.1016/j.optlaseng.2022.107398  Early Access Date: NOV 2022   Published: MAR 2023  

Abstract: This paper presents the modified achromatic Savart Polariscope for constructing broadband spatially modulated snapshot imaging polarimeter. The modified achromatic Savart Polariscope can be made from two different birefringent crystals. The achievements and performances of the modified achromatic Savart Polariscope are demonstrated with numerical simulations. The chromatic variations in spatial carrier frequencies can be reduced by an order of magnitude. The spatially modulated snapshot imaging polarimeter constructed by the modified achromatic Savart Polariscopes can achieve the root mean square errors with a magnitude of 10 - 4 across the spectral range 0.48-0.96 ism as it does in monochromatic light conditions.

Accession Number: WOS:000899357200009

ISSN: 0143-8166

eISSN: 1873-0302

Record 25 of 358

Title: 30 W all-fiber supercontinuum generation via graded-index multimode fiber pumped by picoseconds laser pulse

Author(s): Zhang, T (Zhang, Ting); Hu, XH (Hu, Xiaohong); Pan, R (Pan, Ran); Wang, ZG (Wang, Zhenguang); Zhang, W (Zhang, Wei); Guo, YS (Guo, Yashuai); Feng, Y (Feng, Ye); Wang, YS (Wang, Yishan); Zhao, W (Zhao, Wei)

Source: OPTICS AND LASER TECHNOLOGY  Volume: 159  Article Number: 108943  DOI: 10.1016/j.optlastec.2022.108943  Early Access Date: NOV 2022   Published: APR 2023  

Abstract: We demonstrated an over 30 W all-fiber supercontinuum source based on a four-mode graded-index multimode fiber (GIMF) pumped by around 5 picoseconds laser pulse. Following the evolution of the supercontinuum, it is reasonable to conclude that the discrete spectral peaks in the range 350-700 nm were generated owing to the geometric parametric instability effect and quasi-phase matched harmonic generation, whereas the radiation of dispersive waves, stimulated Raman scattering, and relative effects of optical soliton caused spectral broadening ranging from 700 nm to 1750 nm (and even to 2400 nm). Furthermore, the properties of the supercontinua generated in the four-mode GIMF and the 50/125 standard GIMF were experimentally compared. This com-parison implied that the wavelengths radiated by the geometric parametric instability differed owing to different dispersion values. And the supercontinuum generated by the four-mode GIMF had a flatter spectral profile and a wider wavelength range.

Accession Number: WOS:000905605300002

Author Identifiers:

ISSN: 0030-3992

eISSN: 1879-2545

Record 26 of 358

Title: 160 Gbps capacity and sub-us latency of polarization-independent optical packet switch architecture for free-space optical network using PLZT optical switch

Author(s): Meng, JC (Meng, Jiacheng); Wang, W (Wang, Wei); Xie, NB (Xie, Ningbo); Gao, DR (Gao, Duorui); Zhu, JX (Zhu, Jiaxuan); Bai, ZF (Bai, Zhaofeng); Xie, XP (Xie, Xiaoping)

Source: MODERN PHYSICS LETTERS B  Volume: 36  Issue: 26N27  DOI: 10.1142/S0217984922501457  Early Access Date: NOV 2022   Published: SEP 20 2022  

Abstract: In this paper, we discuss the challenges and limitations of current free-space optical (FSO) networks toward scaling beyond the 100 Gbps switch capacity era while achieving low-latency and high-reliability. Owing to the slowdown of Moore's law, to avoid electronically-induced bottlenecks, we construct an FSO switch network and experimentally evaluate the feasibility of ultrafast optical packet switch architecture based on polarization-independent plomb lanthanum zirconate titanate (PLZT) switch without buffering. The bit error ratio of 160 Gbps (16 lambda x 10) data was validated based on measurements while still preserving the sub-us latency metrics (<400 ns). The experimental results may offer a significant reference for FSO communication and network.

Accession Number: WOS:000889658300002

Author Identifiers:

ISSN: 0217-9849

eISSN: 1793-6640

Record 27 of 358

Title: Observations of Inertia Gravity Waves in the Western Pacific and Their Characteristic in the 2015/2016 Quasi-Biennial Oscillation Disruption

Author(s): He, Y (He, Yang); Zhu, XQ (Zhu, Xiaoqian); Sheng, Z (Sheng, Zheng); He, MY (He, Mingyuan); Feng, YT (Feng, Yutao)

Source: JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES  Volume: 127  Issue: 22  Article Number: e2022JD037208  DOI: 10.1029/2022JD037208  Published: NOV 27 2022  

Abstract: The statistical characteristics of inertia-gravity waves (IGWs) in the troposphere (2-14 km) and lower stratosphere (18-28 km) are analyzed using daily radiosonde observations over six stations in the Western Pacific from 2013 to 2018. Stokes parameter method is used to extract the characteristic parameters of gravity waves (GWs), which are divided into upward and downward propagating waves, and compared with the results of hodograph analysis. In the stratosphere, due to the filtering effect of the background wind field, the IGWs generated in the troposphere mainly propagate eastward with lower frequency range. The tropospheric IGWs have obvious seasonal variation in spectral amplitude and energy, with the maximum in winter and the minimum in monsoon from 2013 to 2018. The stratospheric IGWs are enhanced during phase transition of the quasi-biennial oscillation, when the enhanced easterly wind appears in the lowest stratosphere, accompanied by enhanced wave energy in the troposphere. During the quasi-biennial oscillation disruption in late 2015 and early 2016, the tropospheric wave source excites more intense IGWs propagating upward. After reaching the stratosphere, IGWs with slower phase speed are absorbed by the mean flow, dissipating momentum to the lower stratosphere and generating additional enhanced westward forcing, which may have contributed to the development of the easterly wind within the westerly quasi-biannual oscillation phase.

Accession Number: WOS:000934028000001

Author Identifiers:

ISSN: 2169-897X

eISSN: 2169-8996

Record 28 of 358

Title: Edge effect removal in Fourier ptychographic microscopy via periodic plus smooth image decomposition

Author(s): Pan, A (Pan, An); Wang, AY (Wang, Aiye); Zheng, JF (Zheng, Junfu); Gao, YT (Gao, Yuting); Ma, CW (Ma, Caiwen); Yao, BL (Yao, Baoli)

Source: OPTICS AND LASERS IN ENGINEERING  Volume: 162  Article Number: 107408  DOI: 10.1016/j.optlaseng.2022.107408  Early Access Date: NOV 2022   Published: MAR 2023  

Abstract: Fourier ptychographic microscopy (FPM) is a promising computational imaging technique with high resolution, wide field-of-view (FOV) and quantitative phase recovery. So far, a series of system errors that may corrupt the image quality of FPM has been reported. However, an imperceptible artifact caused by edge effect caught our attention and may also degrade the precision of phase imaging in FPM with a cross-shape artifact in the Fourier space. We found that the precision of reconstructed phase at the same subregion depends on the different sizes of block processing as a result of different edge conditions, which limits the quantitative phase measurements via FPM. And this artifact is caused by the aperiodic image extension of fast Fourier transform (FFT). Herein, to remove the edge effect and improve the accuracy, two classes of opposite algorithms termed discrete cosine transform (DCT) and periodic plus smooth image decomposition (PPSID) were reported respectively and discussed systematically. Although both approaches can remove the artifacts in FPM and may be extended to other Fourier analysis techniques, PPSID-FPM has a comparable efficiency to conventional FPM algorithm. The PPSID-FPM algorithm improves the standard deviation of phase accuracy as a factor of 4 from 0.08 radians to 0.02 radians. Finally, we summarized and discussed all the reported system errors of FPM within a generalized model.

Accession Number: WOS:000899357200005

Author Identifiers:

ISSN: 0143-8166

eISSN: 1873-0302

Record 29 of 358

Title: Effect of mixed magnetic field on physical properties of atmospheric suspended fine particles

Author(s): Han, BB (Han, Binbin); Ming, ZF (Ming, Zhengfeng); Zhao, YH (Zhao, Yuhu); Wen, T (Wen, Tao); Xie, ML (Xie, Meilin)

Source: HELIYON  Volume: 8  Issue: 11  Article Number: e11722  DOI: 10.1016/j.heliyon.2022.e11722  Early Access Date: NOV 2022   Published: NOV 2022  

Abstract: In recent years, the fine particles suspended in the atmosphere, especially the particle size less than 10 mu m, have caused very adverse effects on the climate environment and human health. However, the current research on the causes of air pollution mainly focuses on human activities and weather conditions. Considering the weak magnetism and chargeability of atmospheric fine particles, this study proposed a new view that space electro-magnetic radiation may affect the physical properties of fine particles. We first analyzed the dynamic charac-teristics of magnetic micro-particle in the electromagnetic environment, and built a simulation model in the COMSOL simulation software. Finally, based on the theoretical analysis and simulation results, we built an experimental verification system to evaluate the effects of electromagnetic radiation on the physical properties of micro-particle, and carried out a 30-day control experiment. The experimental results showed that the physical properties such as particle size distribution, mass concentration, and morphology of suspended fine particles in the atmosphere under electromagnetic radiation are significantly different from those under non-electromagnetic radiation environment. It can be inferred that the aggregation, fusion, and deposition of suspended particles in the atmosphere are closely related to the complex electromagnetic environment in space.

Accession Number: WOS:000904327600019

PubMed ID: 36439714

Author Identifiers:

eISSN: 2405-8440

Record 30 of 358

Title: Thermally-induced transverse mode instability: Hopf bifurcation in high-power fiber laser

Author(s): Gao, W (Gao, Wei); Fan, WH (Fan, Wenhui); Ju, P (Ju, Pei); Li, G (Li, Gang); Zhang, YQ (Zhang, Yiqi); Zhang, YP (Zhang, Yanpeng)

Source: RESULTS IN PHYSICS  Volume: 43  Article Number: 106098  DOI: 10.1016/j.rinp.2022.106098  Early Access Date: NOV 2022   Published: DEC 2022  

Abstract: The thermally-induced transverse mode instability (TMI) has become a major challenge for further enhancing the output power of single-mode fiber laser. Even though much work has been done over the past decades, the spontaneous generation process of output spot oscillation has not been well understood yet. Here, we establish a new theoretical model of the thermally-induced TMI in a high-power fiber oscillator and provide a new mechanism explanation from the point of view of nonlinear dynamics. Theoretical analysis shows that the spontaneous oscillation (similar to kHz) of the output spot caused by the thermally-induced TMI is a limit-cycle oscillation via Hopf bifurcation, and the oscillation frequency is proportional to square root of the relaxation rate 1 of thermally-induced refractive index grating (RIG) (vTMI proportional to &RADIC1) when the thermally-induced TMI is initially triggered. Furthermore, the relationship between the threshold power, together with oscillation frequency and several parameters of fiber laser system was also discussed in detail. This work help us better understand the underlying dynamics of the thermally-induced TMI.

Accession Number: WOS:000927573000010

Author Identifiers:

ISSN: 2211-3797

Record 31 of 358

Title: 48 W Continuous-Wave Output From a High-Efficiency Single Emitter Laser Diode at 915 nm

Author(s): Liu, YX (Liu, Yuxian); Yang, GW (Yang, Guowen); Zhao, YM (Zhao, Yongming); Tang, S (Tang, Song); Lan, Y (Lan, Yu); Zhao, YL (Zhao, Yuliang); Demir, A (Demir, Abdullah)

Source: IEEE PHOTONICS TECHNOLOGY LETTERS  Volume: 34  Issue: 22  Pages: 1218-1221  DOI: 10.1109/LPT.2022.3207786  Published: NOV 15 2022  

Abstract: Improving the power and efficiency of 9xx-nm broad-area laser diodes has a great help in reducing the cost of laser systems and expanding applications. This letter presents an optimized epitaxial structure with high power and conversion efficiency. Laser diodes with 230 mu m emitter width and 5 mm cavity length deliver continuous-wave output power up to 48.5 W at 48 A, 30 degrees C, the highest power reported for 9xx-nm single emitter lasers so far. The slope efficiency is as high as 1.23 W/A due to a low internal optical loss of 031 cm(-1) and a high internal efficiency of 96%. The maximum power conversion efficiency reaches 72.6% at 153 W and 67.3% at the operating power of 30 W under a heatsink temperature of 25 degrees C. Life test results show no failure in 1000 hours for 55 laser diodes.

Accession Number: WOS:000864178800005

Author Identifiers:

ISSN: 1041-1135

eISSN: 1941-0174

Record 32 of 358

Title: Gain-switched watt-level thulium-doped fiber laser and amplifier operating at 1.7 μm

Author(s): Xiao, Y (Xiao, Yang); Xiao, XS (Xiao, Xusheng); Liu, LT (Liu, Lutao); Guo, HT (Guo, Haitao)

Source: HIGH POWER LASER SCIENCE AND ENGINEERING  Volume: 10  Article Number: e40  DOI: 10.1017/hpl.2022.33  Published: NOV 13 2022  

Abstract: A 1.7 mu m gain-switched thulium-doped all-fiber laser with a master oscillator power amplifier (MOPA) configuration, utilizing a bandpass fiber filter and a 1550 nm erbium/ytterbium-codoped fiber MOPA, is demonstrated. The influences of pump pulse parameters (repetition rate and pulse duration) and laser cavity structures (ring and linear) on the laser performances were experimentally investigated. To the best of our knowledge, the power quenching and drop were observed in the 1.7 mu m gain-switched thulium-doped fiber lasers for the first time, resulting from the mode-locked-resembling operation and nonlinear effects. Moreover, the fiber ring-cavity laser was more stable than the linear-cavity laser in the time domain and power. Finally, a laser with a maximum average power of 1.687 W, a slope efficiency of 19.7%, a single-pulse energy of 16.87 mu J, a pulse width of 425 ns, a repetition rate of 100 kHz and a peak power of 39.69 W was obtained.

Accession Number: WOS:000895385300001

Author Identifiers:

ISSN: 2095-4719

eISSN: 2052-3289

Record 33 of 358

Title: Effective half-wavelength pitch optical phased array design for aliasing-free 2D beam steering

Author(s): Lei, YF (Lei, Yufang); Zhang, LX (Zhang, Lingxuan); Xue, YL (Xue, Yulong); Ren, YM (Ren, Yangming); Zhang, QH (Zhang, Qihao); Zhang, WF (Zhang, Wenfu); Sun, XC (Sun, Xiaochen)

Source: APPLIED OPTICS  Volume: 61  Issue: 32  Pages: 9423-9428  DOI: 10.1364/AO.474504  Published: NOV 10 2022  

Abstract: We present a method to design an optical phased array (OPA) simultaneously realizing both narrow beam width and aliasing-free 2D beam steering without the need to arrange the antennas at actual half-wavelength pitch. The method realizes an effective half-wavelength pitch in one direction formed by location projection of the antennas. The distances between the antennas in the other direction can be sufficiently large to form an effective large aperture realizing narrow beam width without needing a long grating. The presented method is proven by both theory and numerical simulations to achieve an equivalent grating-lobe-free far field of an ordinary half-wavelength pitch design. One design example exhibits 180 degrees steering with a minimal beam width of 0.4 degrees * 0.032 degrees and a sidelobe suppression ratio of >13 dB. (c) 2022 Optica Publishing Group

Accession Number: WOS:000887083600002

PubMed ID: 36606888

Author Identifiers:

ISSN: 1559-128X

eISSN: 2155-3165

Record 34 of 358

Title: QPSK to BPSK modulation format conversion by phase-sensitive parametric amplification in multi-slot waveguides

Author(s): Wu, X (Wu, Xiao); Li, XF (LI, Xuefeng); Ren, L (Ren, Li); Liu, HJ (Liu, Hongjun)

Source: APPLIED OPTICS  Volume: 61  Issue: 32  Pages: 9609-9615  DOI: 10.1364/AO.472444  Published: NOV 10 2022  

Abstract: The optical modulation conversion of a quadrature phase-shift keying (QPSK) signal to two binary phase-shift keying (BPSK) signals is theoretically realized in a phase-sensitive amplification (PSA) conversion system. We pro-pose a multi-slot silicon-carbon nanotube/polydimethylsiloxane hybrid waveguide to achieve high nonlinearity of 108 W-1 m-1 for improving PSA performance. Constellation diagrams, error vector magnitude, and bit error rate (BER) are used to investigate and measure the performance of the output. The results show that the converted BPSK signal has more than a 10 dB higher signal-to-noise ratio than the QPSK signal with a BER threshold of 10-3. Furthermore, the system has great potential for hierarchical modulation of advanced format signals and long-distance transmission.(c) 2022 Optica Publishing Group

Accession Number: WOS:000887083500002

PubMed ID: 36606901

Author Identifiers:

ISSN: 1559-128X

eISSN: 2155-3165

Record 35 of 358

Title: Ultra-broadband flat-top circular polarizer based on chiral fiber gratings near the dispersion turning point

Author(s): Ren, KL (Ren, Kaili); Yao, KX (Yao, Kexin); Han, DD (Han, Dongdong); Hu, JY (Hu, Jiayue); Yang, L (Yang, Li); Zheng, YP (Zheng, Yipeng); Liang, L (Liang, Lei); Dong, J (Dong, Jun); Zhang, WF (Zhang, Wenfei); Ren, LY (Ren, Liyong)

Source: OPTICS EXPRESS  Volume: 30  Issue: 23  Pages: 41774-41783  DOI: 10.1364/OE.473233  Published: NOV 7 2022  

Abstract: Based on the dual-resonance principle around the dispersion turning point, a scheme of chiral long-period fiber gratings (CLPGs) formed by twisting a high-birefringence (Hi-Bi) fiber is herein proposed to realise ultra-broadband flat-top circular polarizers. The coupling bandwidth is approximately seven times larger than that of traditional CLPGs. In addition, by introducing chirp characteristics in these CLPGs, an ultra-broadband flat-top circular polarizer with similar to 200 nm@3 dB was conveniently achieved. Subsequently, by optimising the chirped CLPGs, a circular polarizer with a bandwidth extinction ratio of approximately 30 dB and a high level of similar to 100 nm at 1 dB was realised. It was shown that the mode-controlling performances of the CLPGs can be remarkably improved, which has significant applications in light-field regulation. Finally, for the first time, it was proved that the CLPG cannot generate a vortex beam.
(c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Accession Number: WOS:000901327200057

PubMed ID: 36366645

Author Identifiers:

ISSN: 1094-4087

Record 36 of 358

Title: Visual attention-based siamese CNN with SoftmaxFocal loss for laser-induced damage change detection of optical elements

Author(s): Kou, JW (Kou, Jingwei); Zhan, T (Zhan, Tao); Zhou, DY (Zhou, Deyun); Xie, Y (Xie, Yu); Da, Z (Da, Zhengshang); Gong, MG (Gong, Maoguo)

Source: NEUROCOMPUTING  Volume: 517  Pages: 173-187  DOI: 10.1016/j.neucom.2022.10.074  Early Access Date: NOV 2022   Published: JAN 14 2023  

Abstract: With high-energy laser irradiating, the laser-induced damages may occur in the surfaces of optical ele-ments in laser facilities. As the laser-induced damage changes can badly affect regular and healthy oper-ation of laser facilities, it is essential to effectively detect real damage changes while suppressing meaningless and spurious changes in captured optical images. In order to achieve high-precision laser -induced damage change detection, this paper presents a novel deep learning model which exploits visual attention-based siamese convolutional neural network with SoftmaxFocal loss and significantly improves the performance of damage change detection. In the proposed model, an end-to-end classification net-work is designed and trained which fuses the spatial-channel domain collaborative attention modules into siamese convolutional neural network thus achieving more efficient feature extraction and represen-tation. For the purpose of addressing the unbalanced distribution of hard and easy samples, a novel loss function which is termed as SoftmaxFocal loss is put forward to train the proposed network. The SoftmaxFocal loss creatively introduces an additive focusing term into original softmax loss which greatly enhances the online hard sample mining ability of the proposed model. Experiments conducted on three real datasets demonstrate the validity and superiority of the proposed model.(c) 2022 Elsevier B.V. All rights reserved.

Accession Number: WOS:000884436700014

ISSN: 0925-2312

eISSN: 1872-8286

Record 37 of 358

Title: Influence of initial tunneling step on the return energy of high-order harmonic generation

Author(s): Gao, XZ (Gao, Xu-Zhen); Landsman, AS (Landsman, Alexandra S.); Cao, HB (Cao, Huabao); Zhang, YP (Zhang, Yanpeng); Wang, YS (Wang, Yishan); Fu, YX (Fu, Yuxi); Pi, LW (Pi, Liang-Wen)

Source: PHYSICAL REVIEW A  Volume: 106  Issue: 5  Article Number: 053105  DOI: 10.1103/PhysRevA.106.053105  Published: NOV 3 2022  

Abstract: To investigate high-order harmonic generation in a monochromatic laser field, we derive an analytical expression for the return energy of an electron as a function of the time interval between ionization and return. We then expand the expression for kinetic energy to second order with respect to the Keldysh parameter.. In this expansion, the zero-order term is the return energy in the simple man model and the second-order term corresponds to corrections to this model. The origin of this additional kinetic energy is frequently attributed to the nonzero exit of the initial tunneling step. Here, we show that this commonly used picture is incomplete. We present a framework to fully understand the additional kinetic energy as resulting from additive contributions of zero-order and second-order velocities. Our results show that the nonzero velocity of the initial tunneling step has a quantifiable effect on the cutoff energy measured in high harmonic generation (HHG). This opens the door to experimentally addressing the question of the initial electron velocity at the tunnel exit, with important implications for the correct calibration of the attoclock, as well as our interpretation of the strong field-ionization process more broadly.

Accession Number: WOS:000912340900004

Author Identifiers:

ISSN: 2469-9926

eISSN: 2469-9934

Record 38 of 358

Title: Research on fretting regime transition of DD6 single-crystal superalloy via femtosecond laser-induced asperity and hardened layer

Author(s): Yu, YQ (Yu, Yanqing); Zhou, LC (Zhou, Liucheng); Li, M (Li, Ming); Cai, ZB (Cai, Zhenbing); Luo, SH (Luo, Sihai); He, WF (He, Weifeng); Fang, XY (Fang, Xiuyang)

Source: APPLIED SURFACE SCIENCE  Volume: 610  Article Number: 155392  DOI: 10.1016/j.apsusc.2022.155392  Early Access Date: NOV 2022   Published: FEB 1 2023  

Abstract: In this study, the fretting wear test was performed on DD6 single-crystal superalloy after femtosecond laser modification (FLM) to evaluate the influence of femtosecond laser-induced asperity and hardened layer on its fretting regime. Results show that the ablation layer with a depth of similar to 3.2 mu m and the deformed layer are formed beneath the surface, with an increase in surface roughness and hardness. The ablation layer is composed of Al2O3, Cr2O3, and spinel structures. However, the diffraction peak and near-surface orientation after FLM remain similar to those in DD6 single-crystal superalloy substrate, indicating that no remarkable phase change and recrystallization occur despite thermal effect during FLM. The hardened layer has lower plasticity, and the asperities are easy to remove, which results in material removal predominating during the friction process. Therefore, the asperity and hardened layer induced by femtosecond laser could change the fretting regime of DD6 single-crystal superalloy from mixed slip regime (MSR) to gross slip regime (GSR). FLM provides a possibility to replace crack initiation with acceptable material removal in special conditions.

Accession Number: WOS:000974368600002

Author Identifiers:

ISSN: 0169-4332

eISSN: 1873-5584

Record 39 of 358

Title: Detection and Recognition of Spatial Non-Cooperative Objects Based on Improved YOLOX_L

Author(s): Ai, H (Ai, Han); Zhang, HF (Zhang, Haifeng); Ren, L (Ren, Long); Feng, J (Feng, Jia); Geng, SN (Geng, Shengnan)

Source: ELECTRONICS  Volume: 11  Issue: 21  Article Number: 3433  DOI: 10.3390/electronics11213433  Published: NOV 2022  

Abstract: In view of the intelligent requirements of spatial non-cooperative target detection and recognition tasks, this paper applies the deep learning method YOLOX_L to the task and draws on YOLOF (You Only Look One-Level Feature) and TOOD (Task-Aligned One-Stage Object Detection), which optimize and improve its detection accuracy to meet the needs of space Task Accuracy Requirements. We improve the FPN (Feature Pyramid Networks) structure and decoupled prediction network in YOLOX_L and perform a validation comparative analysis of the improved YOLOX_L on the VOC2007+2012 and spacecraft dataset. Our experiments conducted on the VOC2007+2012 benchmark show that the proposed method can help YOLOX_L achieve 88.86 mAP, which is higher than YOLOX_L, running at 50 FPS under the image size of 608 x 608. The spatial target detection method based on the improved YOLOX has a detection accuracy rate of 96.28% and a detection speed of 50 FPS on our spacecraft dataset, which prove that the method has certain practical significance and practical value.

Accession Number: WOS:000881019200001

eISSN: 2079-9292

Record 40 of 358

Title: Active Disturbance Rejection Control for Speed Control of PMSM Based on Auxiliary Model and Supervisory RBF

Author(s): Gao, P (Gao, Peng); Su, XQ (Su, Xiuqin); Pan, ZB (Pan, Zhibin); Xiao, M (Xiao, Maosen); Zhang, WB (Zhang, Wenbo); Liu, RY (Liu, Ruoyu)

Source: APPLIED SCIENCES-BASEL  Volume: 12  Issue: 21  Article Number: 10880  DOI: 10.3390/app122110880  Published: NOV 2022  

Abstract: External vibration, shock, unbalanced torque and other uncertain disturbances are mainly transmitted to the motor rotor through the bearing friction. To restrain the uncertain friction disturbances and improve the speed stability of a permanent magnet synchronous motor (PMSM), an optimized active disturbance rejection control (ADRC) algorithm is proposed in this study. Firstly, an auxiliary model of friction and a reduced-order processing method are introduced into extended state observation (ESO) to reduce the burden of single ESO and promote the compensation accuracy of disturbances. In addition, a supervisory radial basis function (SRBF) is employed to supervise and promote the error elimination efficiency of the nonlinear state error feedback rate (NLSEF). The hybrid control algorithm makes up for the deficiency of typical ADRC through the fusion of multiple control quantities. Simulation and experimental results show that the proposed algorithm has strong anti-disturbance performance and effectively solves the problem of low-speed crawling.

Accession Number: WOS:000882579100001

Author Identifiers:

eISSN: 2076-3417

Record 41 of 358

Title: The Opto-Mechanical-Thermal Coupling Analysis and Verification of an All-Aluminum Freeform Imaging Telescope

Author(s): Gao, R (Gao, Rong); Li, JP (Li, Jinpeng); Wang, P (Wang, Peng); Yu, JD (Yu, Jiadong); Xie, YJ (Xie, Yongjun); Mao, XL (Mao, Xianglong)

Source: SYMMETRY-BASEL  Volume: 14  Issue: 11  Article Number: 2391  DOI: 10.3390/sym14112391  Published: NOV 2022