2024

2024

  • Record 397 of

    Title:Static spectroscopic ellipsometer based on division-of-amplitude polarization demodulation
    Author Full Names:Li, Siyuan; Deng, Zhongxun; Quan, Naicheng; Zhang, Chunmin
    Source Title:OPTICS COMMUNICATIONS
    Language:English
    Document Type:Article
    Keywords Plus:MODULATORS
    Abstract:Theoretical and experimental demonstrations of a static spectroscopic ellipsometer are presented. It uses a linear polarizer for generating polarization states to interact with the sample, and three non-polarization beam splitters incorporating four achromatic quarter waveplate/linear analyzer pairs for analyzing the polarization states after the interaction. Compared to previous instruments, the most significant advantage of the described model is that it can obtain the spectral ellipsometric parameters with the same spectral resolution as the spectrometer in the system by a single snapshot.
    Addresses:[Li, Siyuan] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Key Lab Spectral Imaging Technol CAS, Xian, Peoples R China; [Li, Siyuan] Univ Chinese Acad Sci, Beijing, Peoples R China; [Deng, Zhongxun] Shenmu Vocat & Tech Coll, Shenmu, Peoples R China; [Quan, Naicheng] Xian Univ Technol, Sch Mat Sci & Engn, Xian, Peoples R China; [Zhang, Chunmin] Xi An Jiao Tong Univ, Sch Sci, Xian 710049, Peoples R China
    Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Xi'an University of Technology; Xi'an Jiaotong University
    Publication Year:2024
    Volume:552
    Article Number:130115
    DOI Link:http://dx.doi.org/10.1016/j.optcom.2023.130115
    数据库ID(收录号):WOS:001110587300001
  • Record 398 of

    Title:Luminescence properties of ZnSxO1-x:Ce3+ phosphors with tunable short fluorescence lifetime
    Author Full Names:Xing, Xue; Cao, Weiwei; Wu, Zhaoxin; Bai, Xiaohong; Gao, Jiarui; Liang, Xiaozhen; Wang, Bo; Wang, Chao; Shi, Dalian; Lv, Linwei; Bai, Yonglin
    Source Title:MATERIALS LETTERS
    Language:English
    Document Type:Article
    Abstract:Fluorescence lifetime of phosphors is a critical index in the field of high energy physics and astrophysical detection. A series of ZnSxO1-x:0.05Ce(3+) phosphors with tunable short fluorescence lifetime were prepared by performing high temperature solid state reaction method. The phosphors exhibited two mixed phases consisting of the hexagonal phase ZnO and the hexagonal phase ZnS. They are spherical and the average particle size is 2.24 mu m. As the component content of the ZnS in ZnSxO1-x:0.05Ce(3+) phosphors varies, the emission wavelength can be tuned from 448 nm to 495 nm, the short fluorescence lifetime can be tuned within the range of 6 mu s-200 mu s. By performing exponential fitting, we obtained the equation for the variation of fluorescence lifetime of ZnSxO1-x:0.05Ce(3+) phosphors with ZnS fraction.
    Addresses:[Xing, Xue; Cao, Weiwei; Bai, Xiaohong; Gao, Jiarui; Liang, Xiaozhen; Wang, Bo; Wang, Chao; Shi, Dalian; Lv, Linwei; Bai, Yonglin] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Key Lab Space Sci Low Light Level Detect Technol, Xian 710119, Shaanxi, Peoples R China; [Xing, Xue; Wu, Zhaoxin] Xi An Jiao Tong Univ, Sch Elect Sci & Engn, Xian 710049, Shaanxi, Peoples R China; [Xing, Xue; Cao, Weiwei] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Cao, Weiwei] Xi An Jiao Tong Univ, Key Lab Informat Photon Tech, Xian 710049, Shaanxi, Peoples R China
    Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Xi'an Jiaotong University; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Xi'an Jiaotong University
    Publication Year:2024
    Volume:355
    Article Number:135472
    DOI Link:http://dx.doi.org/10.1016/j.matlet.2023.135472
    数据库ID(收录号):WOS:001106393000001
  • Record 399 of

    Title:Speckle-correlation-based non-line-of-sight imaging under white-light illumination
    Author Full Names:Zhou, Meiling; Zhang, Yang; Wang, Ping; Li, Runze; Peng, Tong; Min, Junwei; Yan, Shaohui; Yao, Baoli
    Source Title:OPTICS AND LASER TECHNOLOGY
    Language:English
    Document Type:Review
    Keywords Plus:RECONSTRUCTION; CORNERS
    Abstract:Non-line-of-sight (NLOS) imaging is attracting extensive attention due to its ability to establish the objects hidden from the direct line-of-sight, which prompts potential applications in autonomous driving, robotic vision, biomedical imaging, and other domains. Various NLOS imaging techniques have been successively demonstrated. In this paper, we propose a speckle-correlation-based method to achieve NLOS imaging under white-light illumination. In the proposed method, we process the raw speckle pattern by incorporating the conventional speckle correlation imaging (SCI) with the Zernike polynomial fitting, named ZPF-SCI method, to enhance the performance of the calculated autocorrelation, a key step to achieve optimal image quality. Experimental results demonstrate that our method is effective even in the presence of ambient light, which circumvents the limitation of the conventional SCI that has to be performed in a darkroom. Furthermore, the proposed ZPF-SCI method is insensitive to the angle that the detector deviates from the vertical plane of the optical axis. The quality of the reconstructed image is still acceptable even if the deviation angle reaches 8 degrees. These superiorities facilitate the practical application of the method.
    Addresses:[Zhou, Meiling; Zhang, Yang; Wang, Ping; Li, Runze; Peng, Tong; Min, Junwei; Yan, Shaohui; Yao, Baoli] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xi An Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Zhang, Yang; Yao, Baoli] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Yao, Baoli] Qingdao Marine Sci & Technol Ctr, Qingdao 266200, Peoples R China; [Wang, Ping] Xi An Jiao Tong Univ, Sch Life Sci & Technol, Key Lab Biomed Informat Engn, Minist Educ, Xian 710049, Peoples R China
    Affiliations:State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Xi'an Jiaotong University
    Publication Year:2024
    Volume:170
    Article Number:110231
    DOI Link:http://dx.doi.org/10.1016/j.optlastec.2023.110231
    数据库ID(收录号):WOS:001101007000001
  • Record 400 of

    Title:HQ-I2IT: Redesign the optimization scheme to improve image quality in CycleGAN-based image translation systems
    Author Full Names:Zhang, Yipeng; Hu, Bingliang; Huang, Yingying; Gao, Chi; Yin, Jianfu; Wang, Quang
    Source Title:IET IMAGE PROCESSING
    Language:English
    Document Type:Article
    Abstract:The image-to-image translation (I2IT) task aims to transform images from the source domain into the specified target domain. State-of-the-art CycleGAN-based translation algorithms typically use cycle consistency loss and latent regression loss to constrain translation. In this work, it is demonstrated that the model parameters constrained by the cycle consistency loss and the latent regression loss are equivalent to optimizing the medians of the data distribution and the generative distribution. In addition, there is a style bias in the translation. This bias interacts between the generator and the style encoder and visually exhibits translation errors, e.g. the style of the generated image is not equal to the style of the reference image. To address these issues, a new I2IT model termed high-quality-I2IT (HQ-I2IT) is proposed. The optimization scheme is redesigned to prevent the model from optimizing the median of the data distribution. In addition, by separating the optimization of the generator and the latent code estimator, the redesigned model avoids error interactions and gradually corrects errors during training, thereby avoiding learning the median of the generated distribution. The experimental results demonstrate that the visual quality of the images produced by HQ-I2IT is significantly improved without changing the generator structure, especially when guided by the reference images. Specifically, the Frechet inception distance on the AFHQ and CelebA-HQ datasets are reduced from 19.8 to 10.2 and from 23.8 to 17.0, respectively. In this work, it is demonstrated that the cycle consistency loss and latent regression loss in CycleGAN-based image translation models can be detrimental to image quality. The optimization scheme of CycleGAN-based image translation systems is redesigned and a new translation model named HQ-I2IT is proposed. Experiments demonstrate that the proposed method can significantly improve image quality and translation accuracy.image
    Addresses:[Zhang, Yipeng; Hu, Bingliang; Huang, Yingying; Gao, Chi; Yin, Jianfu; Wang, Quang] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Key Lab Spectral Imaging Technol, 17 Informat Ave, Xian 710119, Shaanxi, Peoples R China; [Zhang, Yipeng; Hu, Bingliang; Huang, Yingying; Gao, Chi; Yin, Jianfu; Wang, Quang] Key Lab Biomed Spect Xian, Xian, Shaanxi, Peoples R China; [Zhang, Yipeng; Huang, Yingying; Gao, Chi; Yin, Jianfu] Univ Chinese Acad Sci, Sch Optoelect, Beijing, Peoples R China
    Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
    Publication Year:2024
    Volume:18
    Issue:2
    Start Page:507
    End Page:522
    DOI Link:http://dx.doi.org/10.1049/ipr2.12965
    数据库ID(收录号):WOS:001087975200001
  • Record 401 of

    Title:Multispectral Image Quality Improvement Based on Global Iterative Fusion Constrained by Meteorological Factors
    Author Full Names:Shi, Yuetian; Fu, Bin; Wang, Nan; Chen, Yaxiong; Fang, Jie
    Source Title:COGNITIVE COMPUTATION
    Language:English
    Document Type:Article
    Abstract:It has been proven that the refractive index is related to meteorological parameters in physics. The temperature changes the atmospheric and lens refractive indices, resulting in image degradation. Image restoration aims to recover the sharp image from the degraded images. It is also the basis of many computer vision tasks. A series of methods have been explored and used in this area. Sometimes, meteorological factors cause image degradation. Most of the existing image restoration methods do not consider meteorological factors' influence on image degradation. How meteorological factors affect image quality is not yet known. A multispectral image dataset with corresponding meteorological parameters is presented to solve the problem. We propose a novel multispectral image restoration algorithm using global iterative fusion. The proposed method firstly enhances image edge features through spatial filtering. Then, the Gaussian function is used to constrain the weights between each channel in the image. Finally, a global iterative fusion method is used to fuse image spatial and spectral features to obtain an improved multispectral image. The algorithm explores the impact of meteorological factors on image quality. It considers the impact of atmospheric factors on image quality and incorporates it into the image restoration process. Extensive experimental results illustrate that the method achieves favorable performance on real data. The proposed algorithm is also more robust than other state-of-the-art algorithms. In this paper, we present an algorithm for improving the quality of multispectral images. The proposed algorithm incorporates the influence of meteorological parameters into the image restoration method to better describe the relationship between different spectral channels. Extensive experiments are conducted to validate the effectiveness of the algorithm. Additionally, we investigate the impact of near-surface meteorological parameters on multispectral image quality.
    Addresses:[Shi, Yuetian; Wang, Nan] Chinese Acad Sci, Key Lab Spectral Imaging Technol CAS, Xian Inst Opt & Precis Mech, Xian 710119, Shaanxi, Peoples R China; [Shi, Yuetian; Wang, Nan] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Fu, Bin] SenseTime Res, Shenzhen 518000, Guangdong, Peoples R China; [Chen, Yaxiong] Wuhan Univ Technol, Sch Comp & Artificial Intelligence, Wuhan 430000, Hubei, Peoples R China; [Fang, Jie] Xian Univ Posts & Telecommun, Sch Telecommun & Informat Engn, Xian 710119, Peoples R China; [Fang, Jie] Corp Shaanxi Wukong Clouds Informat & Technol, Xian 710000, Shaanxi, Peoples R China
    Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Wuhan University of Technology; Xi'an University of Posts & Telecommunications
    Publication Year:2024
    Volume:16
    Issue:1
    Start Page:404
    End Page:424
    DOI Link:http://dx.doi.org/10.1007/s12559-023-10207-7
    数据库ID(收录号):WOS:001085807800001
  • Record 402 of

    Title:Gain-switched 3 μm dysprosium-doped fluoride fiber laser pumped at 1.7 μm
    Author Full Names:Xiao, Yang; Xiao, Xusheng; He, Chunjiang; He, Yuxuan; Guo, Haitao
    Source Title:OPTICS AND LASER TECHNOLOGY
    Language:English
    Document Type:Article
    Keywords Plus:WATT-LEVEL; HIGH-ENERGY; YAG LASER
    Abstract:To the best of our knowledge, we demonstrated a gain-switched 3 mu m dysprosium-doped fluoride fiber laser pumped by a 1706.5 nm pulsed thulium-doped fiber master oscillator power amplifier for the first time. The maximum average power of the 3 mu m pulsed laser was 50 mW with a slope efficiency of 12.3%, a repetition rate of 100 kHz, and a pulse width of 283 ns. This work exhibits the potential of 1.7 mu m pulse pumped dysprosiumdoped fluoride fiber laser as a platform for developing pulsed sources in the 3 mu m region.
    Addresses:[Xiao, Yang; Xiao, Xusheng; He, Yuxuan; Guo, Haitao] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech, Xian 710119, Shaanxi, Peoples R China; [Xiao, Yang; Xiao, Xusheng; He, Yuxuan; Guo, Haitao] Univ Chinese Acad Sci, Ctr Mat Sci & Optoelect Engn, Beijing 100049, Peoples R China; [He, Chunjiang] Harbin Engn Univ, Qingdao Innovat & Dev Base, Qingdao 266500, Peoples R China
    Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Harbin Engineering University
    Publication Year:2024
    Volume:169
    Article Number:110162
    DOI Link:http://dx.doi.org/10.1016/j.optlastec.2023.110162
    数据库ID(收录号):WOS:001096616400001
  • Record 403 of

    Title:Blind deep-learning based preprocessing method for Fourier ptychographic microscopy
    Author Full Names:Wu, Kai; Pan, An; Sun, Zhonghan; Shi, Yinxia; Gao, Wei
    Source Title:OPTICS AND LASER TECHNOLOGY
    Language:English
    Document Type:Article
    Keywords Plus:IMAGE; ALGORITHM; PHASE; RECONSTRUCTION; TRANSFORMATION; NETWORK
    Abstract:Fourier ptychographic microscopy (FPM) is a technique for tackling the trade-off between the resolution and the imaging field of view by combining the techniques from aperture synthesis and phase retrieval to estimate the complex object from a series of low-resolution intensity images captured under angle-varied illumination. The captured images are commonly corrupted by multiple noise, leading to the degradation of the reconstructed image quality. Typically speaking, the noise model and noise level of the experimental images are unknown, and the traditional image denoising methods have limited effect. In this paper we model the FPM forward imaging process corrupted by noise and divide the noise in the captured images into two parts: the signal-dependent part and the signal-independent part. Based on the noise model we propose a novel blind deep-learning based Fourier ptychographic microscopy preprocessing method, termed BDFP, for removing these two components of noise. First, from a portion of the captured low-resolution images, a set of blocks corresponding to the smooth area of the object are extracted to model signal-independent noise. Second, under the assumption that the signal-dependent noise follows a Poisson distribution, we add Poisson noise and signal-independent noise blocks to clean images to form a paired training dataset, which is then used for training a deep convolutional neural network (CNN) model to reduce both signal-dependent noise and signal-independent noise. The proposed blind preprocessing method, combining with typical FPM reconstruction algorithms, is tested on simulated data and experimental images. Experimental results show that our preprocessing method can significantly reduce the noise in the captured images and bring about effective improvements in reconstructed image quality.
    Addresses:[Wu, Kai; Pan, An; Sun, Zhonghan; Shi, Yinxia; Gao, Wei] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Wu, Kai; Shi, Yinxia] Univ Chinese Acad Sci, Beijing 100049, Peoples R China
    Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
    Publication Year:2024
    Volume:169
    Article Number:110140
    DOI Link:http://dx.doi.org/10.1016/j.optlastec.2023.110140
    数据库ID(收录号):WOS:001159160100001
  • Record 404 of

    Title:Secure FSO communication based on optical frequency-hopping technology using delay interferometers
    Author Full Names:Wang, Jian; Jin, Ya; Xie, Zhuang; Chen, Yinfang; Liu, Yu; Zhu, Ninghua
    Source Title:OPTICS COMMUNICATIONS
    Language:English
    Document Type:Article
    Keywords Plus:TRANSMISSION
    Abstract:-A novel optical frequency-hopping (OFH) scheme using optical delay interferometers (DI) is proposed and demonstrated for secure transmission in free space. By performing carrier suppression modulation on the light wave emitted by the laser and connecting the phase modulator (PM) and DI in series, the conversion of the light wave modulated by the Mach-Zehnder modulator (MZM) from phase modulation to intensity modulation can be realized, and finally output the desired optical frequency-shift-keying (OFSK) carrier signal. Meanwhile, by controlling the positions of the frequencies of the positive and negative first-order sideband light waves on the DI frequency response curve, the OFSK signals output by the two ports of the DI can be complemented in the time domain. For the proposed OFH scheme, we carried out simulation experiments of 5 km free-space link transmission and back-to-back transmission with a communication rate of 10 Gbps, and the simulation results proved the feasibility of the scheme. Additionally, we also analyze the security performance of the proposed scheme and give the security space based on the eavesdropping probability.
    Addresses:[Wang, Jian; Jin, Ya; Chen, Yinfang; Liu, Yu; Zhu, Ninghua] Chinese Acad Sci, Inst Semicond, State Key Lab Integrated Optoelect, Beijing 100083, Peoples R China; [Wang, Jian; Jin, Ya; Liu, Yu; Zhu, Ninghua] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Xie, Zhuang] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China
    Affiliations:Chinese Academy of Sciences; Institute of Semiconductors, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS
    Publication Year:2024
    Volume:550
    Article Number:129939
    DOI Link:http://dx.doi.org/10.1016/j.optcom.2023.129939
    数据库ID(收录号):WOS:001086887600001
  • Record 405 of

    Title:Ultrahigh sensitivity terahertz refractive index sensor based on four-inscribed hole defect photonic crystal structure
    Author Full Names:Wen, Jin; Sun, Wei; Liang, Bozhi; He, Chenyao; Xiong, Keyu; Wu, Zhengwei; Zhang, Hui; Yu, Huimin; Wang, Qian
    Source Title:MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
    Language:English
    Document Type:Article
    Keywords Plus:FIBER
    Abstract:We proposed and investigated an ultrahigh sensitivity terahertz (THz) refractive index sensor based on four-inscribed hole defect photonic crystal structure. Due to the formation of resonant modes, the sensing properties can be obtained by shifting the sharp resonance in the transmission spectrum as changing of the analyte refractive index. In addition, the influence of structure parameters on the sensing performance is explored and demonstrated numerically. The numerical results illustrate that the Q-factor and figure of merit reach 323.71 and 167.188 can be obtained under the optimized structural parameters. In particular, an ultrahigh sensitivity of 198.8 mu m/RIU can be realized in the frequency range of 0.777-0.779 THz. The proposed sensor may find significant applications in biochemical sensing systems.
    Addresses:[Wen, Jin; Sun, Wei; Liang, Bozhi; He, Chenyao; Xiong, Keyu; Wu, Zhengwei; Zhang, Hui; Yu, Huimin; Wang, Qian] Xian Shiyou Univ, Sch Sci, Xian, Peoples R China; [Wen, Jin] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech, Xian, Peoples R China; [Wen, Jin] Xian Shiyou Univ, Sch Sci, Xian 710065, Peoples R China
    Affiliations:Xi'an Shiyou University; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Xi'an Shiyou University
    Publication Year:2024
    Volume:66
    Issue:1
    DOI Link:http://dx.doi.org/10.1002/mop.33892
    数据库ID(收录号):WOS:001068423400001
  • Record 406 of

    Title:Optimization of signal-to-noise ratio of laser heterodyne radiometer
    Author Full Names:Sun, Chunyan; He, Xinyu; Xu, Ruoyu; Lu, Sifan; Pan, Xueping; Bai, Jin
    Source Title:MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
    Language:English
    Document Type:Article
    Keywords Plus:MU-M; SPECTROMETER; SPECTROSCOPY; SENSOR; LINE; N2O; CO2
    Abstract:The ground-based laser heterodyne radiometer (LHR), which exhibits the advantages of small size, high spectral resolution, and easy integration, has been used for the remote sensing detection of several gases to meet a wide range of needs. This study aims to optimize the laser heterodyne system for detecting CO2 gas by focusing on existing research. Firstly, using the all-fiber laser heterodyne detection system built by our research group, the power spectrum associated with the radio frequency signals of the detection system is discussed under different conditions: under no irradiation, under sunlight only, under sunlight and laser irradiation at the absorption peak, and under a filter in the spectrum range of 185-270 MHz. Signal-to-noise ratios (SNRs) of the high-resolution spectrum have been obtained using different filter bands of 185-270, 225-270, and 225-400 MHz. Finally, the filter in the 225-270 MHz band, which has the highest SNR, is selected. Consequently, the resolution is improved and the system is further optimized. Furthermore, an optical fiber attenuator is used to change the power of the local oscillator light entering the system, and hyperspectral spectra with varying percentages of input energy and total energy are obtained. When the laser attenuation reaches 40%, the optimal SNR of the system is 486 and can be further improved to meet the expected requirements. This study will provide insights for improving the applicability of laser heterodyne technology in atmospheric sounding.
    Addresses:[Sun, Chunyan; He, Xinyu; Xu, Ruoyu; Lu, Sifan; Pan, Xueping; Bai, Jin] Anqing Normal Univ, Sch Math & Phys, Anqing, Peoples R China; [Sun, Chunyan] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian, Peoples R China; [Sun, Chunyan] Chinese Acad Sci, Anhui Inst Opt & Fine Mech, Hefei, Peoples R China
    Affiliations:Anqing Normal University; Chinese Academy of Sciences; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Hefei Institutes of Physical Science, CAS; Anhui Institute of Optics & Fine Mechanics (AIOFM), CAS
    Publication Year:2024
    Volume:66
    Issue:1
    DOI Link:http://dx.doi.org/10.1002/mop.33857
    数据库ID(收录号):WOS:001093075800001
  • Record 407 of

    Title:Dual-parameter femtosecond mode-locking pulse generation in partially shared all-polarization-maintaining fiber Y-shaped oscillator with a single saturable absorber
    Author Full Names:Bai, Chen; Feng, Ye; Zhang, Weiguang; Zhang, Junying; Zhang, Tong; Mei, Chao; Liu, Pandi; Fan, Zhaojin; Qian, Jiangxiao; Yu, Jia
    Source Title:OPTICS AND LASER TECHNOLOGY
    Language:English
    Document Type:Article
    Keywords Plus:COMB; LASER
    Abstract:We present a design of a mode-locked fiber laser based on a polarization-maintaining (PM) Y-shaped fiber structure, which employs a single semiconductor saturable absorber mirror (SESAM) and a common polarization beam combiner (PBC) to achieve dual-parameter mode-locking femtosecond pulse in two orthogonal po-larization states. The two output pulses have different characteristics, such as repetition frequency (87.3 MHz and 91.3 MHz), average output powers (2.1 mW and 1.9 mW), pulse durations (299 fs and 377 fs) and spectral profiles (centered at 1565.6 nm and 1563.6 nm with spectral width of 9.96 nm and 9.93 nm). The properties of the two pulses are experimentally characterized and their potential applications in areas such as bistable frequency lasers and dual femtosecond optical frequency comb is discussed.
    Addresses:[Bai, Chen; Zhang, Weiguang; Zhang, Junying; Fan, Zhaojin; Qian, Jiangxiao; Yu, Jia] Xian Technol Univ, Sch Optoelect Engn, Xian 710021, Peoples R China; [Feng, Ye; Zhang, Tong] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Mei, Chao] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Dept Aircraft Opt Imaging & Measurement Technol, Xian 710119, Peoples R China; [Liu, Pandi] Xian Shiyou Univ, Sch Sci, Xian 710065, Peoples R China
    Affiliations:Xi'an Technological University; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Xi'an Shiyou University
    Publication Year:2024
    Volume:169
    Article Number:110021
    DOI Link:http://dx.doi.org/10.1016/j.optlastec.2023.110021
    数据库ID(收录号):WOS:001074589200001
  • Record 408 of

    Title:A neighbourhood feature-based local binary pattern for texture classification
    Author Full Names:Lan, Shaokun; Li, Jie; Hu, Shiqi; Fan, Hongcheng; Pan, Zhibin
    Source Title:VISUAL COMPUTER
    Language:English
    Document Type:Article
    Abstract:The CNN framework has gained widespread attention in texture feature analysis; however, handcrafted features still remain advantageous if computational cost needs to take precedence and in cases where textures are easily extracted with few intra-class variation. Among the handcrafted features, the local binary pattern (LBP) is extensively applied for analysing texture due to its robustness and low computational complexity. However, in local difference vector, it only utilizes the sign component, resulting in unsatisfactory classification capability. To improve classification performance, most LBP variants employ multi-feature fusion. Nevertheless, this can lead to redundant and low-discriminative sub-features and high computational complexity. To address these issues, we propose the neighbourhood feature-based local binary pattern (NF-LBP). Inspired by gradient's definition, we extract the neighbourhood feature in a local region by simply using the first-order difference and 2-norm. Next, we introduce the neighbourhood feature (NF) pattern to describe intensity changes in the neighbourhood. Finally, we combine the NF pattern with the local sign component and the centre pixel component to create the NF-LBP descriptor. This approach provides better complementary texture information to traditional local sign pattern and is less sensitive to noise. Additionally, we use an adaptive local threshold in the encoding scheme. Our experimental results of classification accuracy and F1 score on five texture databases demonstrate that our proposed NF-LBP method attains outstanding texture classification performance, outperforming existing state-of-the-art approaches. Furthermore, extensive experimental results reveal that NF-LBP is strongly robust to Gaussian noise and salt-and-pepper noise.
    Addresses:[Lan, Shaokun; Li, Jie; Pan, Zhibin] Xi An Jiao Tong Univ, Sch Elect & Informat Engn, Xian 710049, Peoples R China; [Hu, Shiqi] AVIC Xian Flight Automatic Control Res Inst, Xian 710076, Peoples R China; [Fan, Hongcheng] Air Force Engn Univ, Inst Informat & Nav, Xian 710077, Peoples R China; [Pan, Zhibin] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China
    Affiliations:Xi'an Jiaotong University; Air Force Engineering University; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences
    Publication Year:2024
    Volume:40
    Issue:5
    Start Page:3385
    End Page:3409
    DOI Link:http://dx.doi.org/10.1007/s00371-023-03041-3
    数据库ID(收录号):WOS:001050556700001