2022

• Record 205 of
  
  Title:A Novel NMF Guided for Hyperspectral Unmixing From Incomplete and Noisy Data
  
  Author(s):Dong, Le(1); Lu, Xiaoqiang(2); Liu, Ganchao(3); Yuan, Yuan(4)
  Source: IEEE Transactions on Geoscience and Remote Sensing  Volume: 60  Issue:   DOI: 10.1109/TGRS.2021.3101504  Published: 2022  
  Abstract:The nonnegative matrix factorization (NMF)-combined spatial–spectral information has been widely applied in the unmixing of hyperspectral images (HSIs). However, how to select the appropriate similarity pixels and explore the spatial information and how to adapt the unmixing algorithm to complex data are both great challenges. In this article, we propose a novel unmixing method named spatial–spectral neighborhood preserving NMF (SSNPNMF) for incomplete and noisy HSI data. First, a spatial–spectral kernel regularizer is introduced to preprocess the HSI, which can reduce noise and complete missing elements. Second, a distance metric SSD based on spatial–spectral information is designed to select similar pixels in the image. Subsequently, the spatial–spectral relationship of the selected first k similar pixels is used to reconstruct the image and obtain the reconstruction matrix. Finally, the reconstruction matrix is used to constrain the abundances and improve the unmixing performance. Experimental results on synthetic data and Cuprite data indicate that SSNPNMF has a more effective unmixing performance compared with the state-of-the-art methods. © 2021 IEEE.
  Accession Number: 20220711631676
• Record 206 of
  
  Title:High-throughput Full-color Fourier Ptychographic Microscopy for the Next Generation of Digital Pathologic Imager and Analyser（Invited）
  
  Author(s):Pan, An(1,2); Gao, Yuting(1,2); Wang, Aiye(1,2); Gao, Huiqin(1,2); Ma, Caiwen(1,2); Yao, Baoli(1,2)
  Source: Guangzi Xuebao/Acta Photonica Sinica  Volume: 51  Issue: 7  DOI: 10.3788/gzxb20225107.0751408  Published: July 2022  
  Abstract:Fourier Ptychographic Microscopy （FPM） is a promising computational imaging technique，which tackles the intrinsic trade-off between high resolution and large wide Field Of View（FOV）with a combination of Synthetic Aperture Radar （SAR） and optical phase retrieval. In brief，an LED array beneath the microscope provides illumination of the object from different incident angles. The range of light that can be collected is determined by the Numerical Aperture（NA）of the objective，while parts of the scattering light with a high-angle illumination can also be collected because of light-matter interaction. The low resolution intensity images recorded at each illumination angle are then synthesized in the Fourier domain，thus the object’s high-frequency information can be modulated into the passband of the objective. After an iterative phase reconstruction process，the synthesized information generates a high resolution object image including both intensity and phase properties. Additionally，it preserves the original large FOV as a low-NA objective is used to stitch low resolution images together. Given its flexible setup without mechanical scanning and interferometric measurement，FPM has developed rapidly，which not only acts as a tool to obtain both HR and large FOV but is also regarded as a paradigm to solve a series of trade-off problems，say，the trade-off between angular resolution and spatial resolution in light field imaging. And it may inspire to solve the trade-off between spectral resolution and spatial resolution in imaging spectrometer in the future. In this paper，we comprehensively summarized the development trend of FPM technique in 9 aspects，including high-precision imaging，high-throughput imaging，high-speed or single shot imaging，3D or tomography imaging， mixed state decoupling， spectral dimension （color imaging to hyperspectral imaging），high dynamic range，system extension，and typical applications. Among them，digital pathology is one of the earliest and the most successful applications of FPM. Distinguished from other reviews，we focused on introducing the development process and recent advances in the direction of digital pathology，and divided it into"0-1"，"1-10"，and"10-100"three periods and several stages. Several typical results are also provided. Specifically，the"0-1"refers to the birth of FPM，which breaks the mutual restrictions between FOV and spatial resolution. The"1-10"refers to the exploration period，where the accuracy and stability， limits and bottlenecks， and the efficiency of FPM have been successively discussed and improved. The stage of"10-100"refers to the industrialization period. During this period，researchers focus on market-oriented requirements including acquisition and analysis of color，since full-color imaging is of critical importance for analyzing labeled tissue sections. We point out that FPM has entered the industrialization stage of"10-100"in this application direction. The current task is to build a prototype or product based on FPM. We expect that the product can obtain a spatial resolution of around 200 nm~1 000 nm，a FOV of around 10 mm（2× objective）or 5 mm （4× objective）diameter full-color FPM reconstructed image within 4 s at the DOF of around 0.3~0.5 mm stably and efficiently. We estimate that it can be capable of automation and batch scanning within the next 1~2 years. We analyzed the industry development situations of digital pathology and related market requirements， and discussed the potential of FPM for large-scale socio-economic benefits. We demonstrated that the full-color images with high quality and content and quantitative phase images produced by FPM may play a role of promotion in wide fields，including intraoperative pathology，quantitative Artificial Intelligence （AI） diagnosis， three-dimensional reconstruction， telepathology，teaching and standardized industry criteria. It should also be clarified that as a typical interdisciplinary field，even if the instrument is successfully invented，it only solves issues in the imaging section of the whole process of digital pathology，and there still remain a series of tough tasks to complete. We discussed and classified related scientific problems，technical problems，engineering problems，and industrial problems in detail，whose successful and perfect resolution relies on joint efforts of various parties and constructive introduction of several potential approaches. By combining the FPM solution with the upstream and downstream advanced methods，including the virtual staining，multimodal fusion imaging，label-free observation in situ， non-destructive three-dimensional reconstruction， preliminary screening， and recognition with AI，etc.，we believe that the industry problems will eventually be overcome or alleviated. © 2022 Chinese Optical Society. All rights reserved.
  Accession Number: 20223612693744
• Record 207 of
  
  Title:Adaptive octree 3D image reconstruction based on plane patch
  
  Author(s):Yao, Cheng(1,2); Ma, Caiwen(1,2)
  Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering  Volume: 30  Issue: 9  DOI: 10.37188/OPE.20223009.1113  Published: May 10, 2022  
  Abstract:In this study, an adaptive octree convolutional neural network based on plane patches is proposed for effective 3D shape encoding and decoding. Unlike volume-based or octree-based convolutional neural network (CNN) methods, which represent 3D shapes with the same voxel resolution, the proposed method can use planes and adaptively represent the 3D shapes of octree nodes with different levels. The patch models the 3D shape within each octree node, whereby the patch-based adaptive representation is utilized in the proposed adaptive patch octree convolutional neural network (O-CNN) encoder and decoder for the encoding and decoding of 3D shapes. The adaptive patch O-CNN encoder takes the plane patch normal and displacement as input and performs three-dimensional convolution on the octree nodes of each level, whereas the adaptive patch O-CNN decoder infers each level. The shape occupancy rate and subdivision state of the octree node as well as the best plane normal and displacement of each leaf octree node are estimated. As a general framework for 3D shape analysis and generation, adaptive patch O-CNN not only reduces memory and computational costs but also exhibits better shape generation capabilities than existing 3D-CNN methods. Shape prediction is performed using a single image to verify the efficiency and effectiveness of the generation task of the adaptive O-CNN. The chamfer distance error is 0.274, which is lower than that of OctGen (0.294), resulting in a better reconstruction effect. © 2022, Science Press. All right reserved.
  Accession Number: 20222612294797
• Record 208 of
  
  Title:High-Q Toroidal Dipole Metasurfaces Driven By Bound States in the Continuum for Ultrasensitive Terahertz Sensing
  
  Author(s):Chen, Xu(1); Fan, Wenhui(1); Jiang, Xiaoqiang(1); Yan, Hui(1)
  Source: Journal of Lightwave Technology  Volume: 40  Issue: 7  DOI: 10.1109/JLT.2021.3132727  Published: April 1, 2022  
  Abstract:A novel metallic toroidal dipole (TD) metasurface driven by Friedrich-Wintgen bound states in the continuum (FW-BIC) is theoretically proposed for terahertz (THz) sensing. By tuning the middle gap distance without breaking the symmetry of unit cell, the FW-BIC and quasi-BIC mode can be excited via resonance coupling between dipole modes. Based on the cyclic distribution of anti-aligned magnetic dipoles and the calculated scattering powers, TD resonance is demonstrated qualitatively and quantitatively; also FW-BIC is verified by far-field transmission spectrum and near-field enhancement spectrum. More importantly, it is the first time to exploit this quasi-BIC TD resonance for THz sensing to the best of our knowledge. For micron film sensing with frequency shift (FS) method, numerical results show the sensitivity, the Q-factor and the corresponding figure of merit (FoM) can simultaneously reach 775.7 GHz/RIU, 1016, and 284, respectively. Moreover, for nano film sensing where FS method is inapplicable, the amplitude difference method is utilized and the simulated results show it has superior sensing capability. Our proposed structure opens up an avenue to develop multifunctional and ultrasensitive THz sensors. © 2022 IEEE.
  Accession Number: 20215111368310
• Record 209 of
  
  Title:An embedded system for short wave infrared image enhancement and 3G-SDI display
  
  Author(s):Zhang, Xin(1,2); Liu, Hui(1,2); Li, Xiangwei(1,2)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12328  Issue:   DOI: 10.1117/12.2644212  Published: 2022  
  Abstract:According to the actual requirements of real-time target tracking processing and display of short wave infrared camera with CameraLink interface, an embedded image processing system based on FPGA is designed. The LVDS and GTX ports of FPGA are used to realize CameraLink interface and 3G-SDI interface, it not only improves the integration of the system, but also saves the cost. The adaptive dual platform histogram equalization algorithm is adopted and implemented, which effectively improves the display effect and subsequent processing quality of short wave infrared image. The paper briefly analyzes the algorithm principle of adaptive dual platform histogram, puts forward the adaptive calculation method of dual platform value, studies the implementation method of the algorithm based on Xilinx's FPGA, and gives the solutions of key modules such as adaptive dual platform histogram equalization, image enlarge and 3G-SDI display in FPGA. The experimental results show that the designed embedded image processing system gives consideration to real-time and effectiveness, and realizes the functions of image amplification and high-definition display; The algorithm can calculate and adjust the upper and lower platform values of the histogram in real time according to the scene within 400 µs, effectively enhance the contrast of the image and suppress the background noise. The system has the advantages of strong algorithm adaptability, simple implementation, high integration and low power consumption. It can also be effectively applied to the image acquisition, processing and display of medium wave and long wave infrared cameras. © 2022 SPIE.
  Accession Number: 20230413429151
• Record 210 of
  
  Title:Preparation Technology and Application of Vanadium Dioxide Thin Films （Invited）
  
  Author(s):Shi, Qianqian(1,2); Wang, Jiang(1); Cheng, Guanghua(1)
  Source: Guangzi Xuebao/Acta Photonica Sinica  Volume: 51  Issue: 10  DOI: 10.3788/gzxb20225110.1016002  Published: October 2022  
  Abstract:Vanadium dioxide （VO2） has attracted many attention of researchers since it was discovered in 1959 to have the reversible phase transition from metal to insulator. Before and after the phase transition， its optical， electrical and thermal properties change dramatically. Therefore， vanadium dioxide is widely used in the fields of thermal light control， infrared and optical protection camouflage， ion batteries and chemical sensors. In order to enable domestic researchers to have a more comprehensive and in-depth understanding of this interesting material with broad application prospects， this paper reviews the latest progress of vanadium dioxide film preparation technology in the past five years and its applications in different hot areas. First， we introduce the structure and phase transition mechanism of VO2. When the temperature exceeds 68℃， VO2 will undergo a phase transition from insulator to metal， and its crystal structure will change from monoclinic insulator to rutile metal structure. At the same time， because the crystal structure of vanadium dioxide changes after phase transformation， its corresponding energy band structure also changes. Because the crystal structure and energy band structure of VO2 change suddenly before and after the phase transition， people devote themselves to exploring the physical mechanism of its phase transition. Up to now， there have been many research on the VO2 phase transition mechanism， and also various research methods and devices， but there is no accurate and unified statement. In this paper， we focus on three mainstream explanations of phase transition mechanisms： the first is electron-electron correlation mechanism， i.e. electron correlation driven Mott transition； The second is the electron phonon interaction mechanism， i.e. crystal structure driven Peierls transition. The third is that electron correlation and crystal structure jointly drive VO2 phase transition， and the supporting evidence is summarized. In addition， the phase transition characteristics of vanadium dioxide films are closely related to the preparation technology and process parameters. In the second part of this paper， many new technologies for preparing VO2 thin films， such as high-energy pulsed magnetron sputtering， atomic layer deposition， ink-jet printing， spray pyrolysis and laser direct writing， are introduced in detail， and the advantages and disadvantages of each technology are briefly described. This part provides ideas for researchers on the preparation of materials at the initial stage of experimental design. In performance evaluation， this parameter thermal hysteresis width ΔH reflects the excellent degree of phase transition characteristics of VO2 thin films ΔH will attenuate the phase transition behavior， reduce the working efficiency of the uncooled detector， and also reduce the sensitivity of the near-infrared optical response to temperature， thus reducing ΔH is of great significance for the wide application of VO2 thin films in optoelectronic devices. The third part of this paper focuses on the regulating of the thermal hysteresis width ΔH. Many factors， such as stress， doping and defects， are analyzed. The stress factor is mainly reflected in the selection of substrate materials when preparing films. Different substrates will produce films with different orientations， and different orientations will show different properties. Both doping and oxygen defects change the phase transition properties of the materials by distorting the lattice of the materials in the films. The performance of materials determines the width of their application prospects. VO2 suddenly changes optical， electrical and other properties before and after phase transition， so it is widely used in optoelectronic devices. In recent years， the combination of VO2 thin films and two-dimensional super surface structures is also a hot direction of application. In this paper， we mainly introduce the application of VO2 thin films in the fields of modified smart windows， terahertz modulators， ultrafast optical switches， electrode materials and various sensors. This part can provide inspiration for researchers to explore new applications of VO2 materials. Finally， the problems and prospects faced by the development of VO2 thin films are predicted and evaluated. 1） How to prepare high-purity VO2 thin films. 2） How to reduce the phase transition temperature without reducing the phase transition performance. The solution of these two problems can contribute to the perfect application of VO2 materials in military， laser， and other integrated equipment systems. We sincerely hope that this paper will contribute to the development of new active materials and devices in the field of optoelectronics. © 2022 Chinese Optical Society. All rights reserved.
  Accession Number: 20225213303333
• Record 211 of
  
  Title:Retrieval of Water Parameters from Absorption Spectrum Based on Convolutional Neural Network
  
  Author(s):Liu, Yuyang(1,2); Wang, Xueji(1); Liu, Xiao(1); Liu, Hong(1); Liu, Jiacheng(1,2); Wang, Quan(1); Yu, Tao(1)
  Source: 2022 3rd International Conference on Geology, Mapping and Remote Sensing, ICGMRS 2022  Volume:   Issue:   DOI: 10.1109/ICGMRS55602.2022.9849311  Published: 2022  
  Abstract:In the field of water quality monitoring, the traditional chemical detection methods are time-consuming and laborious, and the operation process is complicated. The technology of absorption spectrum is used to retrieve water quality parameters, which has the advantages of less time-consuming, no secondary pollution, and easy operation. Under the condition of a small dataset, we utilize the convolutional neural network (CNN) combining channel attention module (CAM) to predict three water quality parameters, including suspended solids (SS), chemical oxygen demand (COD), and chromaticity. In this paper, the water quality parameters and corresponding absorption spectra of 50 groups of samples from the mainstream of the Yangtze River were measured by the chemical approach. At the same time, to solve the problem that it is difficult for the neural network to learn effective feature representation under the condition of the small dataset, we propose a loss function combining improved L1 Loss and mean absolute percentage error (MAPE). Our scheme has achieved good results in predicting SS, COD, and chromaticity. The determination coefficients (R2) of SS, COD, and chromaticity of the testing data are 0.93, 0.91, and 0.93 respectively. The results show that the method proposed in this paper can alleviate the over-fitting impact of neural network regression under the condition of small datasets, and at the same time improve the retrieving performance of water quality parameters. © 2022 IEEE.
  Accession Number: 20223812758493
• Record 212 of
  
  Title:Research on Ultrasonic Response Characteristics of Structures Excited by Laser Transient Grating
  
  Author(s):Yao, Dong(1,4); Gao, Bo(2); Song, Yingzheng(3); Li, Qun(3); Gao, Guilong(4)
  Source: Guangzi Xuebao/Acta Photonica Sinica  Volume: 51  Issue: 9  DOI: 10.3788/gzxb20225109.0914001  Published: September 2022  
  Abstract:Ultrasonic Nondestructive Testing （NDT） supports field use and has a strong resolution， which is a key developing method in the field of structural health supervision and testing. In recent years， contact-type technical paths such as patch detection， medium coupling detection， and air coupling detection based on piezoelectric sensors have been formed， which are widely applied to many industries. With the integration of high-quality pulsed laser technology and the research on the mechanism of laser-matter interaction， the detection technology of pulsed laser-excited ultrasound has gradually developed. This technology is expected to solve the problems of surface pollution and fixed detection area caused by traditional piezoelectric-excited adhesive sensors and coating coupling agents. The ultrasonic wave excited by pulsed laser includes longitudinal wave， transverse wave and surface wave， and its propagation velocity is related to the density and elastic constant of the material. In the past， the spot source mode and line source mode of a pulsed laser beam， as well as the line source array mode modulated by lens array and fiber bundle with fixed physical structure， limited the flexibility of spatial expansion of pulsed laser， and also restricted the development of structural response characteristics and signal-structure correlation analysis under the new excitation mode. The disadvantages of pulsed laser excitation are： the monochromatic coherence of laser restricts the modulation ability of beam spot， which leads to the limitation of ultrasonic time-frequency mode， meanwhile， the structural damage threshold limits the energy of pulsed laser， which leads to the shortage of ultrasonic signal intensity. In this paper， the spatial expansion of pulsed laser is combined with laser ultrasonic nondestructive testing technology. Then， the structural response of laser transient grating acting on aluminum alloy plate is studied from two aspects： numerical analysis and experimental research by adopting the idea of numerical analysis to reveal the law and experimental research to verify the method. By deploying observation points at different distances and directions from the center of the grid excitation， the peak gain and the decrease of energy density of the grid excitation signal are obtained for the first time， and the direction angle of near-field enhancement is revealed. The structure size of the simulation model is 50 mm×50 mm×5 mm， the number of grids is 189 062， and the number of computing nodes is 32 028. Mesh encryption is carried out near the center of the upper surface of the aluminum plate， and transition treatment is carried out in a certain range to meet the comprehensive requirements of convergence of the loading area and controllable overall calculation scale. In the field of laser processing and laser processing， aiming at the laser absorption process of rough surface， the reflection-absorption comprehensive model and lumped test method are developed to measure the laser absorption rate. In terms of numerical analysis， the influence of surface roughness on absorptivity under the framework of reflection and absorption model was studied. The excitation process of laser transient grating with a 1mm diameter， 1ns pulse width and 6 mJ single pulse input was simulated， and the comparative analysis of point laser source and line laser source with the same energy was carried out. The numerical results show that the peak value of ultrasonic signal under transient grating excitation was 2~5 times that of point source excitation when the observation distance less than or equal to 4 mm， and the surface energy density of the structure was about 1% of that excited by point source and 12.7% of that excited by line source. The principle of the experiment is that the laser beam spot generated by the pulse laser is split and interfered with by the transient grating module， then， a "bright and dark" laser transient grating is formed. The transient laser grating acts on the surface of the aluminum plate， and the ultrasonic wave is excited in the aluminum plate by thermoelastic effect， which causes the longitudinal displacement of the structural surface. The laser interferometer is used to collect the displacement of the structure surface which is 2 mm and 10 mm away from the center of grating action， and the collected signal is displayed by oscilloscope. The device includes pulse laser， transient grating module， laser interferometer， oscilloscope and aluminum alloy plate. In terms of experimental research， the transient grating module was developed， and the laser transient grating ultrasonic experiments were performed on aluminum plate. The experimental results show that the amplitude of ultrasonic was about 1 nm under 60 kHz high pass filtering， the maximum relative deviation of the surface displacement peak was 8.91%， and the deviation of surface acoustic wave velocity was 6.62%， corresponding to the signal delay at 10 mm from the center of the grating. Synthesize the above analysis， the dispersion of laser beam spot excited by laser transient grating reduces the energy density per unit area of the structure surface， and forms ultrasonic enhancement along the grating direction， which lays a good foundation for improving the signal-to-noise ratio and ensuring the safety of the structure. © 2022 Chinese Optical Society. All rights reserved.
  Accession Number: 20224413027534
• Record 213 of
  
  Title:Automatic observation and correction method of lunar hyperspectral image
  
  Author(s):Wang, Weidong(1,2); Wang, Yihao(1,2); An, Lingping(1,2); Yu, Can(1,2); Wang, Shuang(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12178  Issue:   DOI: 10.1117/12.2631853  Published: 2022  
  Abstract:To realize the long-period and automated data collection of lunar radiation and eliminate the geometric errors of the lunar hyperspectral image during the observation process, this paper proposes a slit-type spectrometer observation method based on the rotating table of the equatorial mount. This method uses a wide field finder-scope to realize automatic moon tracking and positioning; at the same time, it corrects the drift angle and oversampling of the collected raw data. The results show that the full moon situation is the same as the non-full moon situation. This method can effectively find and track the position of the moon's sphere center, and it also corrects the drift and over-sampling of the moon image, realizes accurate and automated long-term observation of the moon, reduces observation errors, and saves observation costs. © 2022 SPIE.
  Accession Number: 20221812066246
• Record 214 of
  
  Title:Research on Image Motion Compensation Technology of Aerial Camera with Fast Sweeping
  
  Author(s):Chen, Weining(1); Cheng, Gong(2); Yang, Hongtao(3); Chang, Sansan(3); Peng, Jianwei(3)
  Source: ACM International Conference Proceeding Series  Volume:   Issue:   DOI: 10.1145/3517077.3517097  Published: January 14, 2022  
  Abstract:In order to improve the efficiency of remote sensing imaging, aerial cameras use vertical swing sweep motion to take imaging. Because the optical axis of the camera rotates at a certain speed in the swing sweep direction, there is a gap between the image formed by the imaging target on the focal plane and the photosensitive medium. Relative motion brings about image motion blur, which will seriously affect the image quality of the camera. Eliminating the problem of image quality degradation caused by this scanning image shift is a problem that must be solved for wide-scan imaging. In the thesis, the mechanism of side-sweeping and the effect of image shifting on the image are analyzed, and the necessity of image-shift compensation is explained. The design adopts an optical mirror-based swing-sweeping image shift. The compensation device performs scanning image motion compensation, and calculates the principle and accuracy of image motion compensation. Through ground image motion compensation test and flight test test, the image motion compensation imaging effect is good, which can meet the requirements of pendulum sweep aerial imaging image motion compensation. © 2022 ACM.
  Accession Number: 20222312201881
• Record 215 of
  
  Title:Control system of intensified ultraviolet spectrometer in near space
  
  Author(s):Chen, Zhen(1); Li, Ran(1); Sun, Xin(1); Yang, Kai(1,3); Wang, Bo(1); Bai, Yonglin(1); Wang, Le(2)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12254  Issue:   DOI: 10.1117/12.2640042  Published: 2022  
  Abstract:The ultraviolet (UV) spectrometer installed on the balloon platform is a cost-effective instrument to observe the UV spectrum of near space, which can meet the needs of biological evolution and planetary material exchange research. A control system of an enhanced UV spectrometer is designed in this paper. Firstly, the framework of the control system is introduced, and the functions of each module are described. Then, the solar angle sensor and automatic air pressure balance device in the enhanced detector module are introduced, making the detector operate safely and reliably in solar radiation and low-pressure environments. Next, the temperature controller is introduced, which can automatically adjust the heating power through the PID algorithm in the embedded chip according to the data collected from the light body and the atmosphere. Finally, the automatic detection mode is described. Among them, the controller can automatically adjust the system gain and integration time according to the spatial ultraviolet radiation intensity information, thus maximizing the efficiency of data. The flight test results of Honghu HH-20-7, HH-20-9 and HH-19-7 show that the spectrometer works normally in the flight experiment. Compared with the ultraviolet radiation in the MODTRAN database, the ultraviolet spectrum data of adjacent space obtained by the spectrometer has the same consistency, but provides a lot of detailed information. © 2022 SPIE.
  Accession Number: 20222612285238
• Record 216 of
  
  Title:Design and analysis of adaptive flexible support for cold optical lens
  
  Author(s):Ke, Shanliang(1); Zhang, Zhaohui(1); Jia, Xinyin(1,2); Li, Libo(1); Chang, Chenguang(1,2); Sun, Lijun(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12166  Issue:   DOI: 10.1117/12.2617758  Published: 2022  
  Abstract:With the increasing demand of infrared detection, the infrared cold optical technology has developed rapidly in recent decades. The low temperature deformation of infrared optical elements is one of the key factors restricting the development of infrared cold optical technology. The processing and assembly of optical subassemblies and support structures are carried out at room temperature and pressure, while the actual working environment of infrared system is relatively low temperature environment, which can vary by 200 degrees Kelvin or more. Therefore, the temperature adaptability of the support structure is strictly required. The optimal design flexible support of the 70mm diameter single crystal lens made by germanium was carried out to ensure that the component surface shape reached (1/6) λ and the natural frequency was above 200HZ at 100K low temperature in this paper. At the same time, the ISIGHT integrated optimization method was used to optimize the flexible support structure. The multi-objective integrated optimization of key dimensions of flexible support was completed, aiming at maximizing the fundamental frequency of the system and minimizing the lens surface shape errors. Finally, the optimal size was selected to complete the flexible structure design. In this paper, an adaptive flexible support structure for cold optical lens with three layers of stress release was designed by multi-objective integrated optimization method. Meanwhile, its performance was verified by low temperature tests. The results verified the reliability and the feasibility of the structure design and analysis. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20220911734971