2024

• Record 109 of
  
  Title:Tailoring the visible light band of Watt-level SCs pumped via picosecond pulse with different Raman extent
  
  Author Full Names:Guo, Yashuai; Wang, Zhenguang; Hu, Xiaohong; Zhang, Ting; Zhang, Zhao; Zhang, Wei; Wang, Yishan

  Source Title:LASER PHYSICS

  Language:English

  Document Type:Article

  Keywords Plus:SUPERCONTINUUM GENERATION

  Abstract:We investigate the supercontinuum (SC) tailoring property by varying the transmission fiber length after the master oscillator power amplifier system. The conversion efficiency of the visible light band is effectively enhanced via tailoring the Raman extent of the injected 30 ps pulse into the nonlinear photonic crystal fiber (PCF). Experimentally, a 3.6 W all-fiber SC spanning from 414 nm to over 1750 nm (@20 dB) is accomplished by using a high duty cycle domestic PCF through precisely controlling the extent of Raman effect. The proposed method is instructive for the further realization of high power SC with an enhanced spectral intensity in the visible light band.

  Addresses:[Guo, Yashuai; Wang, Zhenguang; Hu, Xiaohong; Zhang, Ting; Zhang, Zhao; Zhang, Wei; Wang, Yishan] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Guo, Yashuai; Zhang, Ting; Zhang, Zhao] Univ Chinese Acad Sci, Beijing 100049, 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

  Publication Year:2024

  Volume:34

  Issue:8

  Article Number:85102

  DOI Link:http://dx.doi.org/10.1088/1555-6611/ad552f

  数据库ID（收录号）:WOS:001251409600001
• Record 110 of
  
  Title:Superpixels with Content-Awareness via a Two-Stage Generation Framework
  
  Author Full Names:Li, Cheng; Liao, Nannan; Huang, Zhe; Bian, He; Zhang, Zhe; Ren, Long

  Source Title:SYMMETRY-BASEL

  Language:English

  Document Type:Article

  Abstract:The superpixel usually serves as a region-level feature in various image processing tasks, and is known for segmentation accuracy, spatial compactness and running efficiency. However, since these properties are intrinsically incompatible, there is still a compromise within the overall performance of existing superpixel algorithms. In this work, the property constraint in superpixels is relaxed by in-depth understanding of the image content, and a novel two-stage superpixel generation framework is proposed to produce content-aware superpixels. In the global processing stage, a diffusion-based online average clustering framework is introduced to efficiently aggregate image pixels into multiple superpixel candidates according to color and spatial information. During this process, a centroid relocation strategy is established to dynamically guide the region updating. According to the area feature in manifold space, several superpixel centroids are then split or merged to optimize the regional representation of image content. Subsequently, local updating is adopted on pixels in those superpixel regions to further improve the performance. As a result, the dynamic centroid relocating strategy offers online averaging clustering the property of content awareness through coarse-to-fine label updating. Extensive experiments verify that the produced superpixels achieve desirable and comprehensive performance on boundary adherence, visual satisfactory and time consumption. The quantitative results are on par with existing state-of-the-art algorithms in terms with several common property metrics.

  Addresses:[Li, Cheng; Bian, He; Zhang, Zhe; Ren, Long] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Liao, Nannan] Xidian Univ, Inst Intelligent Control & Image Engn, Xian 710071, Peoples R China; [Huang, Zhe] Wuhan Second Ship Design & Res Inst, Wuhan 430025, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Xidian University

  Publication Year:2024

  Volume:16

  Issue:8

  Article Number:1011

  DOI Link:http://dx.doi.org/10.3390/sym16081011

  数据库ID（收录号）:WOS:001307585400001
• Record 111 of
  
  Title:Redundant-Coded Masked Grid Pattern for Full-Sky Star Identification
  
  Author Full Names:Liao, Jiawen; Wei, Xin; Niu, Axi; Zhang, Yanning; Kweon, In So; Qi, Chun

  Source Title:IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS

  Language:English

  Document Type:Article

  Keywords Plus:CYCLIC FEATURES; ALGORITHM; ROBUST

  Abstract:Full-sky autonomous star identification is one of the key technologies in the research on star sensors. As one of the classical pattern-based star identification methods, the grid algorithm has shown promising performance. Na further modified it to improve its robustness to position noise. However, the inherent alignment star mismatch and pattern inconsistency are still not solved. To address these problems, we propose a novel star identification method. Specifically, we design distance-guided redundant-coded patterns for different alignment stars to alleviate the problem of alignment star mismatch. Then, we create a masked grid pattern to address the inconsistency between the sensor pattern and the catalog pattern. The distances of the reference stars to their corresponding alignment stars are adopted to assist in choosing the correct alignment star, as well as reducing the number of catalog patterns that need to be evaluated. Experimental results on both synthesized and night sky images show that the proposed algorithm is quite robust to false stars, position noise, and magnitude noise. The identification accuracy of this algorithm is 98.43% with standard deviations of position noise is 2.0 pixels and 98.52% with standard deviations of magnitude noise is 0.5 Mv. Moreover, the algorithm obtains an average identification accuracy of 99.6% from night sky images.

  Addresses:[Liao, Jiawen] Chinese Acad Sci, Dept Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Wei, Xin] Northwest Agr & Forestry Univ, Coll Informat Engn, Yang Ling 712199, Peoples R China; [Niu, Axi; Zhang, Yanning] Northwestern Polytech Univ, Sch Comp Sci, Xian 710072, Peoples R China; [Kweon, In So] Korea Adv Inst Sci & Technol, Sch Elect Engn, Daejeon 34141, South Korea; [Qi, Chun] Xi An Jiao Tong Univ, Sch Elect & Informat Engn, Xian 710049, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Northwest A&F University - China; Northwestern Polytechnical University; Korea Advanced Institute of Science & Technology (KAIST); Xi'an Jiaotong University

  Publication Year:2024

  Volume:60

  Issue:4

  Start Page:4343

  End Page:4355

  DOI Link:http://dx.doi.org/10.1109/TAES.2024.3374714

  数据库ID（收录号）:WOS:001291141500062
• Record 112 of
  
  Title:Two-dimensional localized modes in nonlinear systems with linear nonlocality and moiré lattices
  
  Author Full Names:Liu, Xiuye; Zeng, Jianhua

  Source Title:FRONTIERS OF PHYSICS

  Language:English

  Document Type:Article

  Keywords Plus:FRACTIONAL SCHRODINGER-EQUATION; GAP SOLITONS; PHOTONIC CRYSTALS; DYNAMICS; LIGHT

  Abstract:Periodic structures structured as photonic crystals and optical lattices are fascinating for nonlinear waves engineering in the optics and ultracold atoms communities. Moire photonic and optical lattices - two-dimensional twisted patterns lie somewhere in between perfect periodic structures and aperiodic ones - are a new emerging investigative tool for studying nonlinear localized waves of diverse types. Herein, a theory of two-dimensional spatial localization in nonlinear periodic systems with fractional-order diffraction (linear nonlocality) and moire optical lattices is investigated. Specifically, the flat-band feature is well preserved in shallow moire optical lattices which, interact with the defocusing nonlinearity of the media, can support fundamental gap solitons, bound states composed of several fundamental solitons, and topological states (gap vortices) with vortex charge s = 1 and 2, all populated inside the finite gaps of the linear Bloch-wave spectrum. Employing the linear-stability analysis and direct perturbed simulations, the stability and instability properties of all the localized gap modes are surveyed, highlighting a wide stability region within the first gap and a limited one (to the central part) for the third gap. The findings enable insightful studies of highly localized gap modes in linear nonlocality (fractional) physical systems with shallow moire patterns that exhibit extremely flat bands.

  Addresses:[Liu, Xiuye; Zeng, Jianhua] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Ctr Attosecond Sci & Technol, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China; [Zeng, Jianhua] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Zeng, Jianhua] Shanxi Univ, Collaborat Innovat Ctr Extreme Opt, Taiyuan 030006, 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; Shanxi University

  Publication Year:2024

  Volume:19

  Issue:4

  Article Number:42201

  DOI Link:http://dx.doi.org/10.1007/s11467-023-1370-7

  数据库ID（收录号）:WOS:001142014200001
• Record 113 of
  
  Title:Structural vibration frequency monitoring based on event camera
  
  Author Full Names:Lv, Yuanyuan; Zhou, Liang; Liu, Zhaohui; Zhang, Haiyang

  Source Title:MEASUREMENT SCIENCE AND TECHNOLOGY

  Language:English

  Document Type:Article

  Keywords Plus:IDENTIFICATION; VISION

  Abstract:Compared with traditional cameras, event cameras (ECs) have the significant advantages of high temporal resolution, low data redundancy, and microsecond delay, which are beneficial in structural monitoring to extract the dense response of structures in both spatial and temporal dimensions. In this paper, the vibration frequency detection method based on ECs is studied. This study investigates vibration frequency detection methods based on ECs, and proposes two algorithms for vibration frequency detection based on event streams: marker tracking and event count. Experimental verification is conducted through forced vibration experiments. The results indicate that the event count method achieves high-precision measurement of vibration frequencies in the range of 10-190 Hz for different vibration scales, with a maximum relative error of 1% and an average relative error of 0.673%. The marker tracking method demonstrates a maximum relative error of 1.43% and an average relative error of 0.575% in frequency measurement for large-amplitude vibrations. However, as the amplitude decreases, the frequency measurement error increases. When the amplitude is less than 3 pixels, the frequency measurement error exceeds 30%, rendering the measurement results unreliable. This research provides technical support for high-precision structural vibration frequency monitoring and further expands the application of ECs in structural monitoring.

  Addresses:[Lv, Yuanyuan; Zhou, Liang; Liu, Zhaohui; Zhang, Haiyang] Xian Inst Opt & Precis Mech, Chinese Acad Sci, l7 Xinxi Rd, Xian 710119, Peoples R China; [Lv, Yuanyuan; Zhang, Haiyang] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Lv, Yuanyuan; Zhou, Liang; Liu, Zhaohui; Zhang, Haiyang] Chinese Acad Sci, Key Lab Space Precis Measurement Technol, l7 Xinxi Rd, Xian, 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; Chinese Academy of Sciences

  Publication Year:2024

  Volume:35

  Issue:8

  Article Number:85007

  DOI Link:http://dx.doi.org/10.1088/1361-6501/ad42bf

  数据库ID（收录号）:WOS:001222014400001
• Record 114 of
  
  Title:Athermal and Apochromatic Design of Equivalent Two-Component Optical System in 3D Glass Diagram
  
  Author Full Names:Ma, Yingjun; Yang, Hongtao; Chen, Weining; Peng, Jianwei; Guo, Huinan; Zhang, Guangdong

  Source Title:PHOTONICS

  Language:English

  Document Type:Article

  Keywords Plus:LENS DESIGN; GRAPHICAL SELECTION; CHART

  Abstract:In the athermal and apochromatic design of optical systems, the distribution of lens' optical powers and the selection of optical glass and structural materials are crucial. In this paper, an athermal and apochromatic design method is proposed for optical systems with a long focal length, large relative aperture, and wide spectrum. Firstly, a complex optical system composed of multiple lenses is equivalent to a two-component, single-lens system consisting of a replacement and an equivalent lens group. The optical glass for the replacement lens group is selected based on weight and the principle of material replacement in the 3D glass diagram, thus achieving an athermal and apochromatic design. Secondly, an athermal and apochromatic optical system with a focal length of 130 mm, an F-number of 2.0, a spectral range of 480 nm similar to 800 nm, a field of view angle of 22 degrees, and an operating temperature of -40 degrees C similar to+60 degrees C is designed. The modulation transfer function (MTF) at each field of view is greater than 0.6 at 50 lp/mm in the -40 degrees C similar to+60 degrees C temperature range, and the secondary spectrum aberration is 0.0056 mm, which is within the focal depth range of the optical system.

  Addresses:[Ma, Yingjun; Yang, Hongtao; Chen, Weining; Peng, Jianwei; Guo, Huinan; Zhang, Guangdong] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Ma, Yingjun; Peng, Jianwei] Univ Chinese Acad Sci, Beijing 101408, Peoples R China; [Ma, Yingjun; Chen, Weining; Peng, Jianwei; Guo, Huinan] Key Lab Spacecraft Opt Imaging & Measurement Techn, Xian 710119, 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:11

  Issue:8

  Article Number:719

  DOI Link:http://dx.doi.org/10.3390/photonics11080719

  数据库ID（收录号）:WOS:001306740600001
• Record 115 of
  
  Title:Topology Optimization with Explicit Components Considering Stress Constraints
  
  Author Full Names:Ma, Yubao; Li, Zhiguo; Wei, Yuxuan; Yang, Kai

  Source Title:APPLIED SCIENCES-BASEL

  Language:English

  Document Type:Article

  Keywords Plus:DESIGN; MMC

  Abstract:Topology optimization focuses on the conceptual design of structures, characterized by a large optimization space and a significant impact on structural performance, and has been widely applied in industrial fields such as aviation and aerospace. However, most topology optimization methods prioritize structural stiffness and often overlook stress levels, which are critical factors in engineering design. In recent years, explicit topology optimization methods have been extensively developed due to their ability to produce clear boundaries and their compatibility with CAD/CAE systems. Nevertheless, research on incorporating stress constraints within the explicit topology optimization framework remains scarce. This paper is dedicated to investigating stress constraints within the explicit topology optimization framework. Due to the clear boundaries and absence of intermediate density elements in the explicit topology optimization framework, this approach avoids the challenge of stress calculation for intermediate density elements encountered in the traditional density method. This provides a natural advantage in solving topology optimization problems considering stress constraints, resulting in more accurate stress calculations. Compared with existing approaches, this paper proposes a novel component topology description function that enhances the deformability of components, improving the representation of geometric boundaries. The lower-bound Kreisselmeier-Steinhauser aggregation function is employed to manage the stress constraint, reducing the solution scale and computational burden. The effectiveness of the proposed method is demonstrated through two classic examples of topology optimization.

  Addresses:[Ma, Yubao; Li, Zhiguo; Wei, Yuxuan; Yang, Kai] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Ma, Yubao; Wei, Yuxuan; Yang, Kai] Univ Chinese Acad Sci, Sch Optoelect, 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:14

  Issue:16

  Article Number:7171

  DOI Link:http://dx.doi.org/10.3390/app14167171

  数据库ID（收录号）:WOS:001305744800001
• Record 116 of
  
  Title:Analysis of InGaAs/InP Single Photon Avalanche Diodes With Multiplication Width in Sub-Micron
  
  Author Full Names:Qiao, Kai; Chang, Yu; Xu, Zefang; Yin, Fei; Liu, Liyu; Wang, Jieying; Su, Chang; Xu, Linmeng; Fang, Mengyan; Liu, Chunliang; Tian, Jinshou; Wang, Xing

  Source Title:IEEE JOURNAL OF QUANTUM ELECTRONICS

  Language:English

  Document Type:Article

  Keywords Plus:QUANTUM KEY DISTRIBUTION; IMPACT-IONIZATION; NOISE CHARACTERISTICS; DESIGN; PHOTODIODES; PERFORMANCE; CHARGE

  Abstract:InGaAs/InP single-photon avalanche photodiodes (SPADs) is capable of detecting single-photon in the near-infrared spectrum for applications such as quantum communication, fluorescence lifetime imaging, and Light detection and ranging(LIDAR). The effect of multiplication layer width on the performance of SPADs in both linear and Geiger mode have been theoretically studied. Three-types of InGaAs/InP planer SPADs with different multiplication width are fabricated and evaluated. The results of this study suggest that modifying the width of the multiplication layer can regulate the breakdown voltage, punch-through voltage, and dark current of the device. It is found that the measured time jitter is decreasing with the reduction of the width of the multiplication region. These characteristics can be used to optimize the temporal resolution of SPADs device.

  Addresses:[Qiao, Kai; Chang, Yu; Xu, Zefang; Yin, Fei; Liu, Liyu; Wang, Jieying; Su, Chang; Xu, Linmeng; Fang, Mengyan; Tian, Jinshou; Wang, Xing] Chinese Acad Sci, Xian Inst Opt & Precis Mech XIOPM, Key Lab Ultrafast Photoelect Diagnost Technol, Xian 710119, Shaanxi, Peoples R China; [Qiao, Kai; Liu, Chunliang] Xi An Jiao Tong Univ, Sch Elect Sci & Engn, Key Lab Phys Elect & Devices, Minist Educ, Xian 710049, Peoples R China; [Qiao, Kai; Xu, Zefang; Liu, Liyu; Su, Chang; Xu, Linmeng; Fang, Mengyan] Univ Chinese Acad Sci, Ctr Mat Sci & Optoelect Engn, Beijing 100049, 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

  Publication Year:2024

  Volume:60

  Issue:4

  Article Number:4500107

  DOI Link:http://dx.doi.org/10.1109/JQE.2024.3399176

  数据库ID（收录号）:WOS:001240017200001
• Record 117 of
  
  Title:Perfect Off-Axis Optical Vortex Lattice
  
  Author Full Names:Tai, Yuping; Qin, Xueyun; Li, Chenying; Wei, Wenjun; Zhang, Hao; Li, Xinzhong

  Source Title:PHOTONICS

  Language:English

  Document Type:Article

  Abstract:Optical vortex lattices (OVLs) with diverse modes show potential for a wide range of applications, such as high-capacity optical communications, optical tweezers, and optical measurements. However, vortices in typical regulated OVLs often exhibit irregular shapes, such as being narrow and elongated. The resulting increase in asymmetry negatively impacts the efficiency of particle trapping. Additionally, the vortex radii expand with an increase in topological charge (TC), limiting the TC value of the vortices and hindering their ability to fully utilize orbital angular momentum (OAM). Herein, we propose an alternative approach to custom OVLs using off-axis techniques combined with amplitude modulation. Amplitude modulation enables the precise generation of an OVL with perfect vortex properties, known as a perfect off-axis OVL. Further, the number of vortices in the perfect off-axis OVL, the off-axis distances, and the TC can be freely modulated while maintaining a circular mode. This unique OVL will promote new applications, such as the complex manipulation of multi-particle systems and optical communication based on OAM.

  Addresses:[Tai, Yuping; Qin, Xueyun; Li, Chenying; Wei, Wenjun; Zhang, Hao; Li, Xinzhong] Henan Univ, Sch Chem & Chem Engn, Luoyang 471023, Peoples R China; [Tai, Yuping; Qin, Xueyun; Li, Chenying; Wei, Wenjun; Zhang, Hao; Li, Xinzhong] Henan Univ Sci & Technol, Sch Phys & Engn, Luoyang 471023, Peoples R China; [Tai, Yuping; Li, Xinzhong] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China

  Affiliations:Henan University; Henan University of Science & Technology; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics

  Publication Year:2024

  Volume:11

  Issue:8

  Article Number:709

  DOI Link:http://dx.doi.org/10.3390/photonics11080709

  数据库ID（收录号）:WOS:001305305500001
• Record 118 of
  
  Title:Slicing of large-size single crystals by ultrafast laser with external stress assistance
  
  Author Full Names:Wang, Lifeng; Liu, Lili; Wang, Yinan; Li, Xun; Li, Chenchen; Li, Ming

  Source Title:CHINESE OPTICS LETTERS

  Language:English

  Document Type:Article

  Keywords Plus:FEMTOSECOND LASER; DEFORMATION MECHANISM; YAG

  Abstract:The existing single-crystal slicing techniques result in significant material wastage and elevate the production cost of premium-quality thin slices of crystals. Here we report (for the first time, to our knowledge) an approach for vertical slicing of large-size single-crystal gain materials by ultrafast laser. By employing aberration correction techniques, the optimization of the optical field distribution within the high-refractive-index crystal enables the achievement of a continuous laser-modified layer with a thickness of less than 10 mu m, oriented perpendicular to the direction of the laser direction. The compressed focal spot facilitates crack initiation, enabling propagation under external forces, ultimately achieving the successful slicing of a Phi 12 mm crystal. The surface roughness of the sliced Yb:YAG is less than 2.5 mu m. The results illustrate the potential of low-loss slicing strategy for single-crystal fabrication and pave the way for the future development of thin disk lasers.

  Addresses:[Wang, Lifeng; Liu, Lili; Wang, Yinan; Li, Xun; Li, Chenchen; Li, Ming] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China; [Liu, Lili] Univ Chinese Acad Sci, Beijing 100049, 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

  Publication Year:2024

  Volume:22

  Issue:8

  Article Number:81601

  DOI Link:http://dx.doi.org/10.3788/COL202422.081601

  数据库ID（收录号）:WOS:001300587500014
• Record 119 of
  
  Title:Adaptive Image-Defogging Algorithm Based on Bright-Field Region Detection
  
  Author Full Names:Wang, Yue; Yue, Fengying; Duan, Jiaxin; Zhang, Haifeng; Song, Xiaodong; Dong, Jiawei; Zeng, Jiaxin; Cui, Sidong

  Source Title:PHOTONICS

  Language:English

  Document Type:Article

  Keywords Plus:DARK CHANNEL PRIOR; REMOVAL; ENHANCEMENT

  Abstract:Image defogging is an essential technology used in traffic safety monitoring, military surveillance, satellite and remote sensing image processing, medical image diagnostics, and other applications. Current methods often rely on various priors, with the dark-channel prior being the most frequently employed. However, halo and bright-field color distortion issues persist. To further improve image quality, an adaptive image-defogging algorithm based on bright-field region detection is proposed in this paper. Modifying the dark-channel image improves the abrupt changes in gray value in the traditional dark-channel image. By setting the first and second lower limits of transmittance and introducing an adaptive correction factor to adjust the transmittance of the bright-field region, the limitations of the dark-channel prior in extensive ranges and high-brightness areas can be significantly alleviated. In addition, a guide filter is utilized to enhance the initial transmittance image, preserving the details of the defogged image. The results of the experiment demonstrate that the algorithm presented in this paper effectively addresses the mentioned issues and has shown outstanding performance in both objective evaluation and subjective visual effects.

  Addresses:[Wang, Yue; Yue, Fengying; Zeng, Jiaxin; Cui, Sidong] North Univ China, Sch Elect & Control Engn, Taiyuan 030051, Peoples R China; [Wang, Yue; Duan, Jiaxin; Zhang, Haifeng; Song, Xiaodong; Dong, Jiawei; Cui, Sidong] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China

  Affiliations:North University of China; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS

  Publication Year:2024

  Volume:11

  Issue:8

  Article Number:718

  DOI Link:http://dx.doi.org/10.3390/photonics11080718

  数据库ID（收录号）:WOS:001305563200001
• Record 120 of
  
  Title:Dielectric terahertz metasurface governed by symmetry-protected BIC for ultrasensitive sensing
  
  Author Full Names:Yan, Hui; Fan, Wen-Hui; Jiang, Xiao-Qiang; Xu, Chen; Qin, Chong; Wu, Qi

  Source Title:PHYSICA SCRIPTA

  Language:English

  Document Type:Article

  Keywords Plus:TOROIDAL DIPOLE RESONANCE; PHOTONIC BOUND-STATES; CONTINUUM; METAMATERIALS; ULTRATHIN

  Abstract:The non-radiative bound states in the continuum (BIC) have attracted much attention in achieving theoretically infinite quality (Q) factor. In this paper, a dielectric terahertz metasurface with C 4v symmetry is proposed, and a toroidal dipole resonance is easily obtained under incident plane wave. Moreover, by slightly tuning the asymmetry parameter delta to break the in-plane symmetry of the structure (side length perturbation), a magnetic dipole BIC mode radiates as quasi-BIC (QBIC) with extremely narrow linewidth and ultrahigh Q of 1.2 x 104 at delta = 0.4 mu m. It shows significant performance in THz sensing with the sensitivity around 446 GHz/RIU and figure of merit (FoM) up to 2267. The designed metasurface in the case of symmetry-breaking by position perturbation also achieves ultrasensitive sensing. Additionally, the effects of geometric parameters on the resonance modes have been comprehensively investigated. Our work provides a route to design symmetry-protected BIC metasurface with simple structure, and the Q factor as well as resonant frequency can be controlled using a single geometric parameter, which may facilitate designing high-performance metasurface in sensing applications.

  Addresses:[Yan, Hui; Fan, Wen-Hui; Jiang, Xiao-Qiang; Xu, Chen; Qin, Chong; Wu, Qi] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China; [Yan, Hui] Zhongyuan Univ Technol, Sch Phys & Optoelect Engn, Zhengzhou Key Lab Lowdimens Quantum Mat & Devices, Zhengzhou 450007, Peoples R China; [Yan, Hui; Fan, Wen-Hui; Jiang, Xiao-Qiang; Qin, Chong; Wu, Qi] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Fan, Wen-Hui] Shanxi Univ, Collaborat Innovat Ctr Extreme Opt, Taiyuan 030006, Peoples R China

  Affiliations:State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Zhongyuan University of Technology; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Shanxi University

  Publication Year:2024

  Volume:99

  Issue:8

  Article Number:85503

  DOI Link:http://dx.doi.org/10.1088/1402-4896/ad59da

  数据库ID（收录号）:WOS:001259059000001