2024
-
Record 289 of
Title:Phase change thermal control system for space high-power laser diode pumping source array
Author Full Names:Shangguan, Aihong(1); Zhang, Haosu(1); Cao, Yu(1,2); Xie, Youjin(1,2); Zhang, Haiyang(1,3); Jiang, Yongfan(1,3); Wang, Xi(1,3); Su, Shengming(1,3)Source Title:Guangxue Jingmi Gongcheng/Optics and Precision EngineeringLanguage:ChineseDocument Type:Journal article (JA)Abstract:To achieve effective heat dissipation for a space high-power laser diode pumping source array，a phase change thermal control system has been developed. Key components like thermal interface materials （TIM），copper heat sinks，phase-change materials，reinforcing materials，active heaters，and space radiators have been designed and evaluated. Initially，the thermal specifications of the laser diode pumping array are outlined，followed by the thermal control design concepts. A detailed design of the thermal control system was developed，and two thermal control schemes were formulated with and without copper foam filling. Then，the two different schemes were analyzed using NX software. The first scheme reaches a peak temperature of 59. 98 ℃ in 800 s，with the phase-change material surface at 47. 12 ℃ . The second scheme achieves a maximum temperature of 38. 35℃ in 200 s and maintains thermal congruence with the phase-change temperature after 360 s，meeting the 10-40 ℃ specification. Consequently，the thermal control system for the laser diode pumping source is designed and manufactured based on the second scheme，ensuring efficient heat dissipation. ? 2024 Chinese Academy of Sciences. All rights reserved.Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) Key Laboratory of Space Precision Measurement Technology, Chinese Academy of Sciences, Xi'an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:32Issue:19Start Page:2877-2888DOI Link:10.37188/OPE.20243219.2877數(shù)據(jù)庫ID（收錄號）:20244817427981 -
Record 290 of
Title:An innovative 16-bit projection display based on quaternary hybrid light modulation
Author Full Names:Pan, Yue(1,2); Cao, Yajie(1); Xu, Liang(3); Hu, Motong(1); Jiang, Qing(4); Li, Shuqin(4); Lu, Xiaowei(1)Source Title:Optics and Lasers in EngineeringLanguage:EnglishDocument Type:Journal article (JA)Abstract:Conventional spatial light modulators (SLM) can only be used for projecting 8-bit or 10-bit images at normal frame rate. Therefore, commercial high dynamic range (HDR) displays typically focus on boosting the contrast while neglecting to raise the bit-depth. Existing methods for high bit-depth display generally rely on stacking two SLMs to modulate the outgoing beam twice, namely multiplicative modulation, resulting in many troubles such as low optical efficiency, difficulty in pixel-level alignment, and complex image rendering algorithm. In this paper, an innovative quaternary hybrid light modulation (QHLM) based projection display is proposed and realized. By illuminating two parallel digital micro-mirror devices (DMDs) with different light intensities, the quaternary digit-planes (QDs) with four gray levels are able to be modulated rapidly. Aiming at this ability, the quaternary pulse width modulation (QPWM) is incorporated with the quaternary light-intensity modulation (QLM) to fundamentally improve the modulation efficiency compared to the binary light modulation mode. Furthermore, the quaternary digit-plane decomposition (QDD) based image splitting algorithm is adopted to split a high bit-depth image into two images that drive two DMDs respectively. The prototype is designed and built to verify the feasibility of the QHLM based projection display. The experimental results demonstrate that the prototype can project 16-bit images at 220 fps. Through additive modulation of two DMDs in parallel, the QHLM entirely avoids the drawbacks of multiplicative modulation. As a completely different technology, the QHLM has a great potential for HDR projection applications. ? 2024 Elsevier LtdAffiliations:(1) School of Optoelectronic Engineering, Changchun University of Science and Technology, Jilin, Changchun; 130022, China; (2) Key Laboratory of Optical Control and Optical Information Transmission Technology, Ministry of Education, Jilin, Changchun; 130022, China; (3) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Shanxi, Xi'an; 710119, China; (4) Baicheng Central Hospital, Jilin, Baicheng; 137000, ChinaPublication Year:2024Volume:178Article Number:108171DOI Link:10.1016/j.optlaseng.2024.108171數(shù)據(jù)庫ID（收錄號）:20241215789270 -
Record 291 of
Title:High Accurate and Efficient 3D Network for Image Reconstruction of Diffractive-Based Computational Spectral Imaging
Author Full Names:Fan, Hao(1,2); Li, Chenxi(1); Xu, Huangrong(1); Zhao, Lvrong(1,2); Zhang, Xuming(3); Jiang, Heng(3); Yu, Weixing(1,2)Source Title:IEEE AccessLanguage:EnglishDocument Type:Journal article (JA)Abstract:Diffractive optical imaging spectroscopy as a promising miniaturized and high throughput portable spectral imaging technique suffers from the problem of low precision and slow speed, which limits its wide use in various applications. To reconstruct the diffractive spectral image more accurately and fast, a three-dimensional spectrum recovery algorithm is proposed in this paper. The algorithm takes advantage of a neural network for image reconstruction which consists of a U-Net architecture with 3D convolutional layers to improve the processing precision and speed. Numerical experiments are conducted to prove its effectiveness. It is shown that the mean peak signal-to-noise ratio (MPSNR) of the recovered image relative to the original image is improved by 1.8 dB in comparison to other traditional methods. In addition, the obtained mean structural similarity (MSSIM) of 0.91 meets the standard of discrimination to human eyes. Moreover, the algorithm runs in just 0.36 s, which is faster than other traditional methods. 3D convolutional networks play a critical role in performance improvement. Improvements in processing speed and accuracy have greatly benefited the realization and application of diffractive optical imaging spectroscopy. The new algorithm with high accuracy and fast speed has a great potential application in diffraction lens spectroscopy and paves a new way for emerging more portable spectral imaging technique. ? 2013 IEEE.Affiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Key Laboratory of Spectral Imaging Technology of Chinese Academy of Sciences, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, Center of Materials Science and Optoelectronics Engineering, Beijing; 100049, China; (3) The Hong Kong Polytechnic University, Department of Applied Physics, Hong KongPublication Year:2024Volume:12Start Page:120720-120728DOI Link:10.1109/ACCESS.2024.3451560數(shù)據(jù)庫ID（收錄號）:20243717031297 -
Record 292 of
Title:A 85-Gb/s PAM-4 TIA With 2.2-mApp Maximum Linear Input Current in 28-nm CMOS
Author Full Names:Ma, Shuaizhe(1); Yin, Zhenyu(1); Ran, Nianquan(1); Xia, Yifei(1); Yang, Ruixuan(1); Yu, Chuanhao(1); Xu, Songqin(1); Wang, Binhao(2); Qi, Nan(3); Zhang, Bing(1); Shi, Jingbo(4); Gui, Xiaoyan(1); Geng, Li(1); Li, Dan(1)Source Title:IEEE Solid-State Circuits LettersLanguage:EnglishDocument Type:Journal article (JA)Abstract:This letter presents a 100-Gb/s CMOS PAM-4 transimpedance amplifier (TIA) with multimilliampere maximum linear input current. A low-noise high-linearity TIA architecture is proposed, leveraging the reconfigurable front-end (FE) TIA and the continuous time linear equalizer (CTLE) synced at multiple gain modes. Implemented in a 28-nm CMOS technology, the TIA achieves bandwidth of more than 24 GHz with transimpedance gain of 65 dB Ω, while showing an acrlong IRN current density of 10.4 pA/ √ Hz. The maximum linear input current reaches 2.2 mApp and the total harmonic distortion (THD) is less than 3% for an output swing of 600 mVpp, diff. The chip consumes power of 56 mW from 1.4 and 1.1-V supply. ? 2018 IEEE.Affiliations:(1) Xi'an Jiaotong University, Faculty of Electronic and Information Engineering, Xi'an; 710000, China; (2) Institute of Optics and Precision Mechanics, University of Chinese Academy of Sciences, Xi'an; 710119, China; (3) Institute of Semiconductors, University of Chinese Academy of Sciences, Beijing; 100083, China; (4) Beijing University of Posts and Telecommunications, State Key Laboratory of Information Photonics and Optical Communications, School of Integrated Circuits, Beijing; 100876, ChinaPublication Year:2024Volume:7Start Page:50-53DOI Link:10.1109/LSSC.2024.3351683數(shù)據(jù)庫ID（收錄號）:20240315388252 -
Record 293 of
Title:Review of satellite remote sensing technology for near-space atmospheric wind field and temperature field
Author Full Names:He, Weiwei(1); Su, Jiarui(1); Feng, Yutao(2); Wang, Houmao(3); Li, Haotian(1); Wu, Kuijun(1); Li, Faquan(4)Source Title:Hongwai yu Jiguang Gongcheng/Infrared and Laser EngineeringLanguage:ChineseDocument Type:Journal article (JA)Abstract:Significance Near space covers the stratosphere, mesosphere and part of the thermosphere regions of the atmosphere and is a complex transition region between the Earth's atmosphere and space. The detection of its wind and temperature fields is of great engineering and scientific significance for space weather warning and climate change modeling. By monitoring and analyzing atmospheric wind temperature information in the near space, it is possible to gain insight into the dynamical mechanisms of atmospheric circulation, atmospheric chemical processes, and the transport and transformation of various constituents. In addition, the use of atmospheric wind temperature data in the near space makes it possible to optimize satellite orbit design, predict space weather conditions, plan space mission trajectories and ensure the safe operation of satellites and space vehicles. However, due to the limitations of engineering and technical capabilities, global atmospheric wind temperature information in the near space region is very scarce, and remote sensing of atmospheric wind temperature in the near space at the global scale has become a research hotspot in the field of international atmospheric physics and space science. Progress Satellite remote sensing technology is an important means of obtaining atmospheric wind temperature information. In comparison, the development of satellite remote sensing technology for atmospheric temperature field information is more mature, while the vertical detection of the atmospheric wind field, as well as the simultaneous detection of the wind field and temperature field profile, are both difficult and hot spots in the field of satellite remote sensing in the international arena. According to different means of obtaining information, satellite remote sensing technology can be categorized into active and passive detection methods. The active detection method, represented by satellite-based LiDAR, mainly acquires wind field information in the low-altitude region below 30 km. Passive detection, represented by the Atomic Airglow Spectral Imaging Satellite Interferometer (AASIS), acquires wind temperature information in the region above 90 km altitude. For the near space region of 20-100 km, the detection capability of atmospheric wind temperature remote sensing satellite payloads currently operating in orbit is very limited. In view of this, this paper provides a systematic review of the research progress of satellite-based wind temperature detection in near space, aiming to provide reference and inspiration for the research in related fields. First, the current status of atmospheric wind temperature satellite remote sensing technology is introduced, and the detection principles and performance of representative international payloads are summarized. Secondly, starting from three different detection bands, namely near-infrared, long-wave infrared and mid-wave infrared, the target source characteristics, instrument development and detection capability of three types of typical remote sensing technologies for atmospheric wind temperature in near space are discussed in detail, and the applicability and reliability of the three technological solutions under different conditions are summarized through the analysis of the spatial and temporal coverage and the measurement accuracy, which provide important references for the subsequent research. Finally, the future development of satellite remote sensing technology for atmospheric wind and temperature fields in the near space is envisioned. Conclusions and Prospects In summary, satellite-based remote sensing of wind temperatures in near space has developed to some extent over the past decades, but is still insufficient to reach the level of operational detection. Looking forward to the future development trend of satellite-borne wind temperature remote sensing technology in near space, focusing on the spatial coverage capability, time continuity and detection accuracy of atmospheric wind temperature remote sensing payloads, and discussing the engineering difficulty of payload development, it is possible to provide an effective idea for the research and development and application of wind temperature remote sensing satellites in near space. This will provide effective technical means and scientific support for the in-depth study of changes in the atmospheric environment, the improvement of the accuracy of weather forecasts and the optimization of aerospace mission planning, and will make an important contribution to the filling of proximity spatial data and the advancement of meteorological science. ? 2024 Chinese Society of Astronautics. All rights reserved.Affiliations:(1) School of Physics and Electronic Information, Yantai University, Yantai; 264005, China; (2) Xi'an Institute of Optics Precision Mechanic, Chinese Academy of Sciences, Xi'an; 710119, China; (3) National Space Science Center, Chinese Academy of Sciences, Beijing; 100190, China; (4) Institute of Precision Measurement Science and Technology Innovation, Chinese Academy of Sciences, Wuhan; 430071, ChinaPublication Year:2024Volume:53Issue:7Article Number:20240146DOI Link:10.3788/IRLA20240146數(shù)據(jù)庫ID（收錄號）:20243717021685 -
Record 294 of
Title:In Situ Growth of Lead-Free Double Perovskite Micron Sheets in Polymethyl Methacrylate for X-Ray Imaging
Author Full Names:Shi, Jindou(1); Wang, Zeyu(2); Xu, Luxia(3); Wang, Junnan(1); Da, Zheyuan(1); Zhang, Chen(1); Ji, Yongqiang(1); Yao, Qing(1); Xu, Youlong(1); Gaponenko, Nikolai V.(4); Tian, Jinshou(3); Wang, Minqiang(1)Source Title:Advanced Optical MaterialsLanguage:EnglishDocument Type:Journal article (JA)Abstract:Pb-free double-perovskite (DP) scintillators are highly promising candidates for X-ray imaging because of their superior optoelectronic properties, low toxicity, and high stability. However, practical applications require Pb-free DP crystals to be ground and mixed with polymers to produce scintillator films. Grinding can compromise film uniformity and optical properties, thereby affecting imaging resolution. In this study, an in situ fabrication strategy is proposed to facilitate the crystalline growth of Pb-free Cs2AgInxBi1-xCl6 micron sheets in polymethyl methacrylate in a single step. By adjusting the In3+/Bi3+ ratio, Cs2AgIn0.9Bi0.1Cl6/PMMA composite films (CFs) with excellent scintillation properties are obtained, including a light yield of up to 32000 photons per MeV and an X-ray detection limit of 87 nGyairs?1. This strategy also enabled the production of large Cs2AgIn0.9Bi0.1Cl6/PMMA CFs, which demonstrated favorable flexibility and stability, fabricating products with advanced eligibility for commercial applications. The CFs exhibited outstanding performances in X-ray imaging, producing high-resolution structures and providing a new avenue for the development of Pb-free DP materials in fields such as medical imaging and safety detection. ? 2024 Wiley-VCH GmbH.Affiliations:(1) Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education International Center for Dielectric Research&Shannxi Engineering Research Center of Advanced Energy Materials and Devices, Xi'an Jiaotong University, Xi'an; 710049, China; (2) Frontier Institute of Science and Technology (FIST), and Micro- and Nano-technology Research Center of State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an; 710049, China; (3) Xi'an Institute of Optics and Precision Mechanics, Shaanxi, Xi'an; 710119, China; (4) Belarusian State University of Informatics and Radioelectronics, P. Browki 6, Minsk; 220013, BelarusPublication Year:2024Volume:12Issue:22Article Number:2400691DOI Link:10.1002/adom.202400691數(shù)據(jù)庫ID（收錄號）:20242716645353 -
Record 295 of
Title:Scale and pattern adaptive local binary pattern for texture classification[Formula presented]
Author Full Names:Hu, Shiqi(1,2); Li, Jie(1); Fan, Hongcheng(3); Lan, Shaokun(1); Pan, Zhibin(1,4)Source Title:Expert Systems with ApplicationsLanguage:EnglishDocument Type:Journal article (JA)Abstract:Local binary pattern (LBP) with a fixed sampling template is sensitive to scale changes. Furthermore, under rotation changes or noise corruptions, one uniform LBP pattern can be corrupted to fall into a non-uniform pattern which loses its discrimination power to describe the corresponding texture feature. To overcome these two main drawbacks, we propose a scale and pattern adaptive local binary pattern (SPALBP). Firstly, in the gradient-based sampling radius adaptive scheme, eight directional adaptive sampling radius of each center pixel can be obtained by using its eight Kirsch gradient values. Secondly, in the noise and rotation robust neighborhood sampling scheme, three neighborhood sampling templates are used to extract three kinds of averaging neighborhood pixels. Thirdly, for each center pixel, three kinds of LBPriu2 patterns can be extracted by sampling these three kinds of averaging neighborhood pixels along eight directional adaptive sampling radius. Finally, an optimal SPALBP uniform pattern can be adaptively selected from these three LBPriu2 patterns. Hence, all SPALBP patterns show more robustness against scale changes, rotation changes and noise corruptions. Extensive experiments are conducted on four standard texture databases: Outex, UIUC, CUReT and XU_HR. Comparing with state-of-the-art LBP-based variants, the proposed SPALBP method consistently shows superior performance both in dramatic environment changes and high-levels of noise conditions, meanwhile it maintains a lower texture feature dimension. ? 2023 Elsevier LtdAffiliations:(1) Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an; 710049, China; (2) The AVIC Xi'an Flight Automatic Control Research Institute, Xi'an; 710076, China; (3) The Institute of Information and Navigation, Air Force Engineering University, Xi'an; 710077, China; (4) State Key Laboratory of Transient Optics and Photonics, Chinese Academy of Sciences, Xian; 710119, ChinaPublication Year:2024Volume:240Article Number:122403DOI Link:10.1016/j.eswa.2023.122403數(shù)據(jù)庫ID（收錄號）:20240215355772 -
Record 296 of
Title:Radiative Transfer Characteristics of the 1.27 um O2(a1Δg) Airglow in Limb-Viewing
Author Full Names:Wang, Dao-Qi(1); Wang, Hou-Mao(2); He, Wei-Wei(1); Hu, Xiang-Rui(1); Li, Juan(3); Li, Fa-Quan(4); Wu, Kui-Jun(1)Source Title:Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral AnalysisLanguage:ChineseDocument Type:Journal article (JA)Abstract:Because the 1.27 um O2(a1Δg)) airglow radiation has the advantages of strong radiation signal, large space span and weak self-absorption effect, it is an important target source for near-space atmospheric remote sensing. In addition, it has important scientific significance and application value, such as research on the dynamics and thermal characteristics of the middle and upper atmosphere, global greenhouse gas detection, and three-dimensional tomography of ozone concentration. Firstly, based on the photochemical model of O2(a1Δg), the generation and annihilation mechanisms of O2(a1Δg) airglow were studied. The volume emission rate profile of O2(a1DELg) airglow was calculated on this basis. Based on the spectral intensity and Einstein coefficients given by HITRAN, two methods for calculating the spectral distribution of O2(a1Δg) airglow were proposed. Using the latest molecular spectral parameters, photochemical reaction rate constant and F 10.7 solar ultraviolet flux, combined with the volume emission rate profile information of O2(a1Δg) airglow calculated by photochemical reaction model. The radiative transfer theoretical model of the 1. 27 um O2(a1Δg) airglow in limb-viewing was developed by using a line-by-line integration algorithm. The influence of the self-absorption effect on the spectral intensity of airglow radiation at different tangent heights is analyzed. Then, the O2(a1Δg) airglow radiation spectrum of the target layer is obtained by processing the airglow radiation of the O2 molecule near the infrared atmospheric band measured by scanning imaging absorption spectrometer for atmospheric chartography (SCIAMACHY) under the limb-viewing by onion peeling algorithm. Spectral integration algorithm is used to retrieve the volume emission rate profile of O2(a1Δg)) airglow. Finally, the reliability and rationality of the radiative transfer theoretical model of the 1. 27 jim O2(a1Δg)) airglow in limb-viewing is verified by comparing the radiation spectrum and the volume emission rate profile obtained from the theoretical calculation and retrieval of the SCIAMACHY instrument. Regarding the comparison results, factors that contribute to the limb radiation intensity and volume emission rate of O2(a1Δg) airglow are analyzed. Analyses show that theoretical calculations agree with measured satellite results in the altitude region above 50 km. However, the deviation between the two increases gradually with the decrease of altitude because the satellite remote sensing in the middle and low altitude regions are seriously affected by the self-absorption effect and atmospheric scattering effect in limb-viewing. Additionally, compared with the spectral line intensity parameter given by the HITRAN database, the O2(a1Δg)) airglow limb radiation model based on Einstein coefficients is more consistent with the measured satellite results. Establishing the radiative transfer theoretical model of the 1. 27 um O2(a1Δg) airglow in limb-viewing provides a theoretical foundation for atmospheric remote sensing in near space. ? 2024 Science Press. All rights reserved.Affiliations:(1) School of Physics and Electronic Information, Yantai University, Yantai; 264005, China; (2) National Space Science Center, Chinese Academy of Sciences, Beijing; 100190, China; (3) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (4) Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan; 430071, ChinaPublication Year:2024Volume:44Issue:4Start Page:1088-1097DOI Link:10.3964/j.issn.1000-0593(2024)04-1088-10數(shù)據(jù)庫ID（收錄號）:20241515862842 -
Record 297 of
Title:Automatic detection of face mask wearing based on polarization imaging
Author Full Names:Li, Bosong(1); Li, Yahong(1); Li, Kexian(1); Fu, Yuegang(2); Ouyang, Mingzhao(2); Jia, Wentao(3)Source Title:Optics ExpressLanguage:EnglishDocument Type:Journal article (JA)Abstract:Amidst the global health crisis sparked by the coronavirus pandemic, the proliferation of respiratory illnesses has captured worldwide attention. An increasing number of individuals wear masks to mitigate the risk of viral transmission. This trend has posed a critical challenge for the development of automatic face mask wearing detection systems. In response, this paper proposed what we believe is a novel face mask wearing detection framework DOLP-YOLOv5, which innovatively employs polarization imaging to enhance the detection of face mask by leveraging the unique characteristics of mask surfaces. For extracting essential semantic details of masks and diminish the impact of background noise, the lightweight shuffle attention (SA) mechanism is integrated in the backbone. Further, a Content-Aware Bidirectional Feature Pyramid Network (CA-BiFPN) is applied for feature fusion, sufficiently integrating the information at each stage and improving the ability of the feature presentation. Moreover, Focal-EIoU loss is utilized for the bounding box regression to improve the accuracy and efficiency of detection. Benchmark evaluation is performed on the self-constructed polarization face mask (PFM) dataset compared with five other mainstream algorithms. The mAP50-95 of DOLP-YOLOv5 reached 63.5%, with 3.08% and 4.44% improvements over the YOLOv8s and YOLOv9s, and achieved a response speed of 384.6f/s. This research not only demonstrates the superiority of DOLP-YOLOv5 in face mask wearing detection, but also has certain reference significance for other detection of polarization imaging. ? 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.Affiliations:(1) Research Institute of Photonics, Dalian Polytechnic University, Dalian; 116034, China; (2) School of Opto-Electronic Engineering, Changchun University of Science and Technology, Changchun; 130022, China; (3) Key Laboratory of Space Precision Measurement Technology, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xian; 710119, ChinaPublication Year:2024Volume:32Issue:20Start Page:34678-34693Article Number:#528929DOI Link:10.1364/OE.528929數(shù)據(jù)庫ID（收錄號）:20244017128299 -
Record 298 of
Title:Optimal design of a gravitational wave telescope system for the suppression of stray light
Author Full Names:Liang, Rong(1,2); Zhou, Xiaojun(1); Xu, Huangrong(1); Wu, Dengshan(1); Li, Chenxi(1); Yu, Weixing(1,2)Source Title:Applied OpticsLanguage:EnglishDocument Type:Journal article (JA)Abstract:For gravitational wave detection, the telescope is required to have an ultra-low wavefront error and ultra-high signal-to-noise ratio, where the power of the stray light should be controlled on the order of less than 10-10. In this work, we propose an alternative stray light suppression method for the optical design of an off-axis telescope with four mirrors by carefully considering the optimal optical paths. The method includes three steps. First, in the period of the optical design, the stray light caused by the tertiary mirror and the quaternary mirror is suppressed by increasing the angle formed by the optical axes of the tertiary mirror and the quaternary mirror and reducing the radius of curvature of the quaternary mirror as much as possible to make sure the optical system provides a beam quality with a wavefront error less than λ/80. Next, the stray light could satisfy the requirement of the order of 10-10 when the level of roughness reaches 0.2 nm, and the pollution of mirrors is controlled at the level of CL100. Finally, traditional stray light suppression methods should also be applied to mechanics, including the use of the optical barrier, baffle tube, and black paint. It can be seen that the field stop can efficiently reduce stray light caused by the secondary mirror by more than 55% in the full field of view. The baffle tube mounted on the position of the exit pupil can reduce the overall stray light energy by 5%, and the difference between the ideal absorber (absorption coefficient is 100%) and the actual black paint (absorption coefficient is 90%) is 3.2%. These simulation results are confirmed by theMonte Carlo method for a stray light analysis. Based on the above results, one can conclude that the geometry structure of the optical design, the quality of mirrors, and the light barrier can greatly improve the stray light suppression ability of the optical system, which is vital when developing a gravitational wave telescope with ultra-lowstray light energy. ? 2024 Optica Publishing Group.Affiliations:(1) Key Laboratory of Spectral Imaging Technology of Chinese Academy of Sciences, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, No. 17, Xinxi Road, Xian; 710119, China; (2) Center of Mechanics Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:63Issue:8Start Page:1995-2003DOI Link:10.1364/AO.502610數(shù)據(jù)庫ID（收錄號）:20241215786774 -
Record 299 of
Title:Streak tube imaging lidar with kilohertz laser pulses and few-photons detection capability
Author Full Names:Fang, Mengyan(1,2); Qiao, Kai(1); Yin, Fei(1); Xue, Yanhua(1); Chang, Yu(1); Su, Chang(1,2); Wang, Zhengzheng(1); Tian, Jinshou(1,2,3); Wang, Xing(1)Source Title:Optics ExpressLanguage:EnglishDocument Type:Journal article (JA)Abstract:Lidar using active light illumination is capable of capturing depth and reflectivity information of target scenes. Among various technologies, streak tube imaging lidar (STIL) has garnered significant attention due to its high resolution and excellent precision. The echo signals of a STIL system using single laser pulse are often overwhelmed by noise in complex environments, making it difficult to discern the range of the target. By combining high-frequency laser pulses with the repetitive sweep circuit, the STIL system enables efficient detection of few-photons signal in weak-light environments. Additionally, we have developed a robust algorithm for estimating the depth and reflectivity images of targets. The results demonstrate that this lidar system achieves a depth resolution better than 0.5 mm and a ranging accuracy of 95 um. Furthermore, the imaging of natural scenes also validates the exceptional 3D imaging capability of this system. ? 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.Affiliations:(1) Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi'an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Shaanxi, Xi'an; 710119, China; (2) Center of Materials Science and Optoelectronics Engineering, University of Chinese, Academy of Sciences, Beijing; 100049, China; (3) Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan; 030006, ChinaPublication Year:2024Volume:32Issue:11Start Page:19042-19056DOI Link:10.1364/OE.520620數(shù)據(jù)庫ID（收錄號）:20242116152071 -
Record 300 of
Title:Research of laser atmospheric propagation of large-aperture antenna measurement
Author Full Names:Zhang, Xuan(1); Gao, Ming(1); Wang, Hu(1,2,3,4,5); Lin, Shangmin(2,3,4); Jin, Yu(2,3); Lai, Yunqiang(2,3); Lv, Hong(1); He, Wenlong(2,3)Source Title:Proceedings of SPIE - The International Society for Optical EngineeringLanguage:EnglishDocument Type:Conference article (CA)Conference Title:8th International Conference on Speckle Metrology, Speckle 2023Conference Date:October 18, 2023 - October 20, 2023Conference Location:Xi'an, ChinaConference Sponsor:Changchun Institute of Optics, Fine Mechanics, and Physics; Wuhan Red Star Yang Science and Technology Co., Ltd.; Xi'an Micromach Technology Co., Ltd.; Xi'an Startin Optronics Co., Ltd.Abstract:Laser measurement technology is widely used in antenna main reflector and subreflector deformation or pose measurement. Based on the laser measurement technology, atmospheric turbulence caused by the atmospheric characteristics or the convergence effect of the antenna itself will affect the refractive index disturbance during laser propagation, which affects the accuracy of the laser measurement of the antenna deformation or pose. In order to solve the problem of laser atmospheric propagation deflection caused by atmospheric turbulence on the near-ground of a large-aperture antenna, firstly, this paper decomposes the laser atmospheric propagation path into multiple isotropic air layers, calculates the atmospheric refractive index of each air layer, obtains the atmospheric refractive index of the whole laser propagation path through curve fitting methods, and then assesses the laser deflection. Secondly, the turbulence intensity under sunny daytime and cloudy nighttime are evaluated, the laser spot position deviation is compared and analyzed, and the matching relationship among turbulence intensity, theoretical deviation of the laser spots, and actual spot deviation is obtained. Finally, the deflection of laser atmospheric propagation is fitted and calculated by measuring environmental data matched to the actual experimental data of the Nanshan 26m radio telescope antenna, which verifies the effectiveness and feasibility of the proposed method. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Affiliations:(1) Xi'an Technological University, No.2 Xuefuzhonglu Road, Shaanxi, Xi'an; 710021, China; (2) Xi an Institute of Optics and Precision Mechanics, Chinese Academy of Science, No.17 Xinxi Road, Shaanxi, Xi'an; 710119, China; (3) University of Chinese Academy of Sciences, No.1 Yanqihu East Rd, Huairou District, Beijing; 101408, China; (4) Xi an Space Sensor Optical Technology Engineering Research Center, No.17 Xinxi Road, Shaanxi, Xi'an; 710119, China; (5) Key Laboratory of Space Precision Measurement Technology, Chinese Academy of Sciences, No.17 Xinxi Road, Shaanxi, Xi'an; 710119, ChinaPublication Year:2024Volume:13070Article Number:130700XDOI Link:10.1117/12.3021213數(shù)據(jù)庫ID（收錄號）:20241315797460