2023
2023
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Record 313 of
Title:Design of all-sky airglow imaging spectrometers in the middle and upper atmosphere
Author(s):Li, Xijie(1); Li, Yong(1); Fu, Di(1); Feng, Yutao(1)Source: Optik Volume: 287 Issue: null Article Number: 171087 DOI: 10.1016/j.ijleo.2023.171087 Published: September 2023Abstract:In order to detect the distribution of gravity waves in the middle and upper atmosphere, an all-sky airglow imaging spectrometer is designed to measure the airglow. It has the detection advantages of ultrawide field of view (FOV), large relative aperture and high signal-to-noise ratio (SNR). It can obtain the spectral images of OH (715–850 nm / 880–930 nm) and OI (630 nm) in the height range of 87–250 km. The whole design method of telecentric objective splicing relay zoom group is used to effectively suppress the spectral drift less than 0.2 nm, which meets the requirements of narrow bandwidth filters. The field experiments in northwest China show that the all-sky airglow imaging spectrometer can continuously acquire airglow spectral images with high SNR in both OH channel and OI channel without focusing in the temperature range of 0–45 ℃, and the images obtained in OH channel have obvious gravity wave phenomenon after star point removal and geometric correction. ? 2023 Elsevier GmbHAccession Number: 20232614311952 -
Record 314 of
Title:Reversible lateral optical force on phase-gradient metasurfaces for full control of metavehicles
Author(s):Li, Tianyue(1); Kingsley-Smith, Jack J.(2); Hu, Yanhui(2); Xu, Xiaohao(3,4); Yan, Shaohui(3,5); Wang, Shuming(1,6); Yao, Baoli(3,5); Wang, Zhenlin(1); Zhu, Shining(1,6)Source: Optics Letters Volume: 48 Issue: 2 Article Number: null DOI: 10.1364/OL.478979 Published: January 15, 2023Abstract:Photonics is currently undergoing an era of miniaturization thanks in part to two-dimensional (2D) optical metasurfaces. Their ability to sculpt and redirect optical momentum can give rise to an optical force, which acts orthogonally to the direction of light propagation. Powered by a single unfocused light beam, these lateral optical forces (LOFs) can be used to drive advanced metavehicles and are controlled via the incident beam's polarization. However, the full control of a metavehicle on a 2D plane (i.e. forward, backward, left, and right) with a sign-switchable LOF remains a challenge. Here we present a phase-gradient metasurface route for achieving such full control while also increasing efficiency. The proposed metasurface is able to deflect a normally incident plane wave in a traverse direction by modulating the plane wave's polarization, and results in a sign-switchable recoil LOF. When applied to a metavehicle, this LOF enables a level of motion control that was previously unobtainable. ? 2023 Optica Publishing Group.Accession Number: 20230413411340 -
Record 315 of
Title:An efficient wide area imaging scheme based on spiral scanning
Author(s):Chang, Sansan(1,2); Li, Xiang(1); Yang, Kai(3)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12557 Issue: null Article Number: 125572O DOI: 10.1117/12.2652233 Published: 2023Abstract:There are three common scanning schemes for large area imaging for airborne camera-multi lens splicing, circumferential scanning or reciprocating scanning. However, the lens splicing form requires multiple lenses, and the system is cumbersome. The circumferential scanning imaging obtains a wide area image through azimuth continuous scanning and the field of view in the pitching direction of this imaging method is a fixed value. And the imaging efficiency of reciprocating scanning form is low due to the need for multiple mechanism turns. In this paper, a new spiral scanning scheme method over large area imaging is proposed, which carries the area array camera on the two-dimensional platform with external azimuth gimbal and internal pitch gimbal. Scanning in azimuth combined with pitch motion, the spiral scanning trail is composed for wide-area imaging, and this method requires only one area array camera and only one rotation in pitch direction in one imaging process, which has high imagery efficiency. At the same time, the spiral dynamic scanning algorithm which can isolate attitude disturbance and compensate flight movement to achieve the scanning imaging for large area of the specified area is deduced. Then the implementation form of the scanning method is also derived. Finally, we take some simulation to test the method. The results show that the spiral scanning algorithm can compensate the attitude disturbance and aircraft attitude disturbance, and can obtain the staring imaging of 254km2 (mapping radius of 9km) in 3.8 seconds, when the field of view angle of area array camera is 7.5 °×11.25 °, the flight speed is 360km/h, the azimuth attitude disturbance is 15 °, the pitch attitude disturbance is 15 °, and the roll attitude disturbance is 8 °, at the flight altitude of 7500m. Therefore, the spiral scanning algorithm scheme is suitable for wide area imaging of moving carrier and has certain significance for the research of wide area scanning imaging system. ? 2023 SPIE.Accession Number: 20230813600535 -
Record 316 of
Title:Extraction and analysis algorithms for Sanxingdui cultural relics based on hyperspectral imaging
Author(s):Qiu, Shi(1); Zhang, Pengchang(1); Li, Siyuan(1); Hu, Bingliang(1)Source: Computers and Electrical Engineering Volume: 111 Issue: null Article Number: 108982 DOI: 10.1016/j.compeleceng.2023.108982 Published: November 2023Abstract:The Sanxingdui Ruins site, situated in Sichuan Province, China, constitutes a significant component of the ancient Shu culture. Confronted with the challenge of excavating and analyzing cultural relics, this study introduces hyperspectral methods for the first time, utilizing the cultural relics unearthed from sacrificial pits. It proposes a novel algorithm for the extraction and analysis of Sanxingdui cultural relics, while also establishing a comprehensive data acquisition and analysis system. The specific innovations of this research are as follows: 1) Acquiring spectral curves of representative materials such as ivory, jade, bronze, and stone pillars, and constructing a spectral database. 2) Introducing the Dual-encoder UNet (D-Unet) model from a spatial perspective to achieve preliminary extraction of cultural relics. 3) Proposing an unsupervised Fuzzy C-means (FCM) algorithm from a spectral perspective to analyze the material properties of cultural relics. Experimental results demonstrate that the proposed algorithm successfully achieves the extraction and analysis of Sanxingdui cultural relics. Ablation experiments further reveal that the algorithm yields excellent results in scenarios involving exposed cultural relics, semi-exposed cultural relics on the ground, and typical cultural relics. Moreover, the algorithm can be extended to other aspects of archeological excavation and analysis. During the experiment, it was observed that: 1) The cultural relics' surfaces contain distinctive substances, tentatively identified as proteins, suggesting the presence of textile capabilities in the ancient Shu civilization. 2) An unearthed bronze mask exhibits structural asymmetry, contrasting with other highly refined artifacts. Through intelligent synthesis technology analysis, a totem-like target was discovered at the center of the eyebrow, potentially associated with the veneration of eyes in Sanxingdui cultural relics, thereby providing additional validation of the algorithms effectiveness. ? 2023 Elsevier LtdAccession Number: 20234214879691 -
Record 317 of
Title:Electrostatic MEMS micromirror servo control for micro laser communication terminal
Author(s):Wang, Xuan(1,2); Han, Junfeng(1,2); Wang, Chen(1,2); Su, Xiuqin(1,2); Liu, Peng(1,2); Cao, Yu(1,2); Wang, Fan(1,2); Jing, Feng(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12702 Issue: null Article Number: 1270211 DOI: 10.1117/12.2679932 Published: 2023Abstract:CubeSats are gaining popularity in low-Earth orbit networks due to their low cost, fast response, and the potential and ability to form constellations. But establishing optical communication links between CubeSats is a daunting task. Laser transmission links require very strict beam pointing stability, and for small satellites with strict size, weight, and power (SWaP) requirements, it is imperative to research light and miniaturized laser communication terminals. Electrostatic micro-electromechanical systems (MEMS) mirrors are currently the most effective devices for realizing SWaP terminals in the field of optical communication. Therefore, this paper mainly studies the servo control of electrostatic MEMS mirrors for micro-miniature laser communication terminals. By using the position error feedback of the photodetector, the servo control requirements of high response speed and high robustness are realized. ? 2023 SPIE.Accession Number: 20233714726098 -
Record 318 of
Title:Dynamical analysis and structural optimisation of angular contact ball bearing
Author(s):Luo, Shan(1,2); Li, Zhiguo(1,2); Cheng, Zhiyuan(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12557 Issue: null Article Number: 1255731 DOI: 10.1117/12.2652154 Published: 2023Abstract:Spaceborne two-dimensional turntable is the main carrier of the space camera and other optoelectronic equipment, and the stability of the thin-walled angular contact ball bearings used in its shaft system will affect the control accuracy and service life of the satellite. Research on slip rate, the deviation ratio of centroid whirl velocity and vibration of bearing with different pocket clearances, outer clearances and velocity and axial loads. For 71928AC type angular contact ball bearing, when pocket clearance is between 0.30-0.40mm, outer clearance is 1.60mm, the cage of bearing has better stability. According to the experimental results, after the parameter optimization, the bearing stability is enhanced. The research results provide a theoretical basis for the optimal design of angular contact ball bearing cages. ? 2023 SPIE.Accession Number: 20230813600475 -
Record 319 of
Title:Evaporation characteristics of Er3+doped silica fiber and its application in the preparation of whispering gallery mode lasers
Author(s):Li, Angzhen(1); Ward, Jonathan M.(2); Tian, Ke(3); Yu, Jibo(4); She, Shengfei(5); Hou, Chaoqi(5); Guo, Haitao(5); Chormaic, Síle Nic(6); Wang, Pengfei(3)Source: arXiv Volume: null Issue: null Article Number: null DOI: null Published: May 12, 2023Abstract:The fabrication of whispering gallery lasers (WGL) is used to experimentally evaluate the evaporation rate (mol/μm) and ratio (mol/mol) of erbium and silica lost from a doped fiber during heating. Fixed lengths of doped silica fiber are spliced to different lengths of undoped fiber and then evaporated by feeding into the focus of a CO2laser. During evaporation, erbium ions are precipitated in the doped silica fiber to control the erbium concentration in the remaining SiO2, which is melted into a microsphere. By increasing the length of the undoped section, a critical point is reached where effectively no ions remain in the glass microsphere. The critical point is found using the lasing spectra of the whispering gallery modes in microspheres with equal sizes. From the critical point, it is estimated that, for a given CO2laser power, 6.36 × 10-21mol of Er3+is lost during the evaporation process for every cubic micron of silica fiber. This is equivalent to 1.74 × 10-7mol of Er3+lost per mol of SiO2evaporated. This result facilitates the control of the doping concentration in WGLs and provides insight into the kinetics of laser-induced evaporation of doped silica. Copyright ? 2023, The Authors. All rights reserved.Accession Number: 20230187573 -
Record 320 of
Title:Optimizing the Accuracy of Microcomb-Based Microwave Photonic Transversal Signal Processors
Author(s):Sun, Yang(1); Wu, Jiayang(1); Li, Yang(1); Xu, Xingyuan(2); Ren, Guanghui(3); Tan, Mengxi(3); Chu, Sai Tak(4); Little, Brent E.(5); Morandotti, Roberto(6); Mitchell, Arnan(3); Moss, David J.(1)Source: Journal of Lightwave Technology Volume: 41 Issue: 23 Article Number: null DOI: 10.1109/JLT.2023.3314526 Published: December 1, 2023Abstract:Microwave photonic (MWP) transversal signal processors offer a compelling solution for realizing versatile high-speed information processing by combining the advantages of reconfigurable electrical digital signal processing and high-bandwidth photonic processing. With the capability of generating a number of discrete wavelengths from micro-scale resonators, optical microcombs are powerful multi-wavelength sources for implementing MWP transversal signal processors with significantly reduced size, power consumption, and complexity. By using microcomb-based MWP transversal signal processors, a diverse range of signal processing functions have been demonstrated recently. In this article, we provide a detailed analysis for the processing inaccuracy that is induced by the imperfect response of experimental components. First, we investigate the errors arising from different sources including imperfections in the microcombs, the chirp of electro-optic modulators, chromatic dispersion of the dispersive module, shaping errors of the optical spectral shapers, and noise of the photodetector. Next, we provide a global picture quantifying the impact of different error sources on the overall system performance. Finally, we introduce feedback control to compensate the errors caused by experimental imperfections and achieve significantly improved accuracy. These results provide a guide for optimizing the accuracy of microcomb-based MWP transversal signal processors. ? 1983-2012 IEEE.Accession Number: 20233814765871 -
Record 321 of
Title:Numerical modeling of multi-point side-pumped mid-infrared erbium-doped fluoride fiber lasers
Author(s):Xiao, Yang(1,2); He, Yuxuan(3,4); Chen, Yun(5); Xu, Xiaochuan(5); Xiao, Xusheng(1,2); Guo, Haitao(1,2)Source: Optics Express Volume: 31 Issue: 15 Article Number: null DOI: 10.1364/OE.493570 Published: July 17, 2023Abstract:We investigate the power scaling and thermal management of multi-point side-pumped 2.825 μm heavily-erbium-doped fluoride fiber lasers by numerical simulation. The 4-point (or 6-point) erbium-doped fluoride fiber laser with polished erbium-doped fluoride fiber-based side-pump couplers delivers an output laser power of over 100 W at each launched 981 nm pump power of 100 W (or 75 W). Meanwhile, the core temperature increases of the gain fiber tips are below 1 K, making it possible for a highly reflective fiber Bragg grating to work stably in high-power operation. Once the preparation processes of these erbium-doped fluoride fiber-based side-pump couplers and endcaps with effective coatings are mature, the proposed multi-point side-pumped erbium-doped fluoride fiber lasers with some feasibility may theoretically pave the way for the development of hundred-watt mid-infrared fiber lasers with effective thermal management. ? 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.Accession Number: 20233114482365 -
Record 322 of
Title:Target detection using spectral unmixing
Author(s):Zhang, Lei(1); Qiao, Kai(1); Wu, Yinhua(2); Li, Siyuan(3)Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering Volume: 31 Issue: 21 Article Number: null DOI: 10.37188/OPE.20233121.3156 Published: November 2023Abstract:The statistics of background information in hyperspectral target detection are often interfered by target information， and the presence of a large number of mixed pixels in hyperspectral images will further deepen this interference. In this study， we proposed a target detection algorithm using spectral unmixing to accurately calculate background information and significantly reduce the interference of target pixels on background statistical information. First， we obtained the abundance coefficient corresponding to the target end member by spectral unmixing and target similarity judgment. We combined it with the spectral angle coefficient to generate a reasonable background weighting coefficient for weighted constrained energy minimization （CEM） target detection， effectively improving the statistical accuracy of background information of mixed pixels. Second， we generated a preliminary result of target detection by utilizing the abundance coefficient corresponding to the target end member and spectral angle coefficient and fused with the weighted CEM target detection result to optimize further， effectively improving the robustness of the algorithm and target detection accuracy. Experimental results showed that the algorithm proposed in this study has good target detection performance for simulated or real hyperspectral images. The algorithm has strong robustness and effectively improves target detection accuracy. Compared with the traditional CEM algorithm， weighted CEM algorithm based on spectral angle， and normalized abundance coefficient as the target result the AUC of this study was promoted by an average of 0.071 2， 0.031 2， and 0.015 0， respectively. The proposed algorithm has strong practicability in hyperspectral applications. ? 2023 Chinese Academy of Sciences. All rights reserved.Accession Number: 20234715080081 -
Record 323 of
Title:Development status of low temperature infrared detection technology
Author(s):Ke, Shanliang(1,2); Hu, Binliang(1); Zhang, Zhaohui(1); Zhang, Zhinan(1); Sun, Lijun(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12617 Issue: null Article Number: 1261729 DOI: 10.1117/12.2664844 Published: 2023Abstract:Infrared detection technology is getting more and more attention, with the rapid development of infrared remote sensing application. Among them, low temperature infrared spectroscopy detection technology is an important development direction in the future. Infrared detection technology is a kind of target detection technology, using the infrared radiation characteristics of substances to different wavelengths. Infrared spectrometer is an important instrument to realize infrared detection technology. This type of spectrometer has been popularized and applied. The imaging spectrometer can reflect the spatial information and spectral characteristics of the observation target. With the improvement of spectral imaging resolution, the signal-to-noise ratio of imaging system is required to increase, which is the technical difficulty of low-temperature infrared spectroscopy. At present, noise reduction through low temperature is the main method. Therefore, infrared detection technology to work in a lower temperature direction. Furthermore, it promotes the progress of low temperature infrared spectroscopy technology. This paper summarizes and compares the development status of low temperature infrared spectrum detection technology. Thus, the key technology of low temperature detection spectrum is extracted. The low temperature infrared detection technology is classified according to the development status of low temperature infrared optics, low temperature support technology and low temperature refrigeration technology. Summarize the shortcomings of domestic existing technology and look forward to the future development direction. ? 2023 SPIE.Accession Number: 20232114130706 -
Record 324 of
Title:Research on Active Disturbance Rejection Control of Voice Coil Motor Based on Improved Particle Swarm Optimization
Author(s):Wang, ZiYuan(1,2); Ge, Wei(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12557 Issue: null Article Number: 125572Z DOI: 10.1117/12.2651636 Published: 2023Abstract:As a high-precision position actuator, the voice coil motor (VCM) is widely used in technology of segmented mirror and mirror shape correction in space telescope. In response to the adverse effects of internal and external disturbances on the precision positioning of the VCM, an improved particle swarm optimization (PSO) based active disturbance rejection control (ADRC) VCM position control model is proposed in this paper. Our model is able to present a reasonable solution to the problem that ADRC has numerous parameters which are knotty to configure. In order to prevent precocious convergence or falling into local optimal, a variable weight factor search method is proposed. MATLAB and Simulink are employed for co-simulation and control experiment are designed. The simulation results show that compared with traditional PID control, the control model designed in this paper has better dynamic performance, higher tracking accuracy and better disturbance rejection performance, and it is suitable for high-precision position control under complex environment with a bright engineering application prospect. ? 2023 SPIE.Accession Number: 20230813600546