2023

• Record 301 of
  
  Title:Annular sampling cylindrical vector beam polarization measurement error analysis based on the Stokes parameter method
  
  Author(s):Chang, Lingying(1); Chi, Liang(1); Chen, Kui(1); Qiu, Yuehong(2); Li, Jiayi(1); Zhang, Youbiao(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12959  Issue: null  Article Number: 129590R  DOI: 10.1117/12.3007450  Published: 2023  
  Abstract:Cylindrical vector beams(CVBs) are spatially non-uniform polarization distributions. It has been widely used in microscopic imaging, particle manipulation, beam shaping, and other fields. Accurate measurement of the CVBs polarization state distribution is one of the research problems. In order to analyze the influence of systematic errors on the CVBs polarization parameters, the measurement errors of the polarization azimuthal AOP under annular sampling are investigated in this paper. Firstly, the generation of CVBs and the measurement principle of Stokes parametric method is introduced; secondly, the radial and angular vector beam intensity images and the AOP distribution under different annular sampling are simulated; then, the variation of R=256 intensity error IΔ with the polarization azimuth error θ in the range of [-2°,2°] is analyzed. Finally, the single error and the coupling error are analyzed and discussed. The simulation results show that the intensity errors IΔ1 and IΔ2 are the same with the θ, and IΔ3 and IΔ4 are the same with the θ. Under the single error, the absolute error values of the AOPs with mutual residual angles are similar. The maximum absolute error of AOP of IΔ1 and IΔ2 is 1° (@45°) and the maximum relative error is 2.59% (@30°); the maximum absolute error of AOP of IΔ3 and IΔ4 is 1°(@0°) and the maximum relative error is 5.12% (@15°). Under the coupling error, the absolute AOP error of IΔ1 and IΔ2 increases with the increase θ, with the maximum value of 2° (@45°) and the maximum relative error of 5.25% (@30°); the absolute AOP error of IΔ3 and IΔ4 decreases with the increase of θ, with the maximum value of 2°(@0°), with a relative maximum error of 10.40% (@15°). The study provides an error data reference for CVBs polarization detection. It can provide technical support for the application of CVBs in different fields. © 2023 SPIE.
  Accession Number: 20240215330019
• Record 302 of
  
  Title:Particle aggregation/disaggregation and sorting using woven spiral beams
  
  Author(s):Tai, Y.P.(1,2); Wei, W.J.(1); Zhang, H.(1); Ma, H.X.(3); Li, X.Z.(1,2,4)
  Source: Applied Physics Letters  Volume: 123  Issue: 19  Article Number: 191109  DOI: 10.1063/5.0180252  Published: November 6, 2023  
  Abstract:Spiral beams (SBs) have attracted increasing attention in structured light fields owing to their chirality and rich modes. However, the wrench force of existing SBs is uncontrollable and nonadjustable, which greatly limits the complex applications of particle manipulation. To address this issue, we proposed a woven spiral beam (WSB) with a controllable force field. The WSB was constructed by reshaping multispiral beams woven through an SB. The proposed WSB has flexible adjustable intensity lobes, which are easy to modulate independently, including size, position, helicity, and phase gradient. Furthermore, the WSBs were used to experimentally execute important particle manipulations, such as aggregation/disaggregation and sorting. This study provides an alternative scheme for the functional applications of SBs, which leads to different application scenarios in optical manipulations. © 2023 Author(s).
  Accession Number: 20234615057705
• Record 303 of
  
  Title:Total reflection optical design of AOTF imaging spectrometer
  
  Author(s):Chang, Lingying(1); Wang, Xinyou(1); Qiu, Yuehong(2); Wang, Guanru(1); Lv, Yifan(1); Liang, Chi(1); Chen, Kui(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12617  Issue: null  Article Number: 126173O  DOI: 10.1117/12.2666109  Published: 2023  
  Abstract:A total reflection optical system of AOTF (acousto-optic tunable filters) imaging spectrometer was designed, which adopts the confocal scheme, consisting of the front lens, AOTF and projection lens. AOTF is the field stop of the optical system. Both subsystems are quasi-telecentric systems that can effectively eliminate the parallax when the subsystems are connected and facilitate the installation of the system. The initial structural parameters are determined by the third-order aberration theory of the coaxial three-mirror optical system. This off-axis total reflection optical system is unobstructed by adding the field of view off-axis, tilt, and decentration, with a spectral range of 0.4-1.7μm, a focal length of 150mm, and a full field of view of 4.68°. The simulation result is shown that the modulation transfer function (MTF) is greater than 0.54 in the 0.4-1.7μm band, which is close to the diffraction limit, and the systematic distortion value is less than 0.1%. © 2023 SPIE.
  Accession Number: 20232114130572
• Record 304 of
  
  Title:Fringe Pattern Orthogonalization Method by Generative Adversarial Nets
  
  Author(s):Feng, Leijie(1); Du, Hubing(1); Zhang, Gaopeng(2); Li, Yanjie(1); Han, Jinlu(1)
  Source: Guangzi Xuebao/Acta Photonica Sinica  Volume: 52  Issue: 1  Article Number: 0112003  DOI: 10.3788/gzxb20235201.0112003  Published: January 2023  
  Abstract:Optical measurement techniques, such as interferometry, moiré techniques, and digital holography, are the most popular noncontact approaches for measuring three-dimensional (3D) object surfaces in terms of non-invasive, fast, and accurate evaluation. Usually, the property of the measured quantity is encoded in the phase of the intensity distribution of the fringe pattern, which can be decoded by phase retrieval, in other words, the recovery of a complex-valued signal from the sampled intensity patterns. In this way, phase demodulation of the fringe pattern plays a crucial role in the ubiquitous optical measurements. Among various single frame phase demodulation techniques, the high-frequency fringe pattern demodulation technique, such as Fourier transform profilometry, sampling moiré method and spatial carrier phase-shifting have been intensively studied and are mainly based on known analytical models of measurement systems, such as harmonic representation of the intensity of fringe patterns. But for low-frequency fringe pattern, phase reconstruction from only a single interferogram is difficult, especially for those including closed fringes. Sign ambiguity during the single-frame demodulation is one of the main problems that impede the development of single-frame interferometry. In this case, fringe pattern orthogonalization plays a very important role in low-frequency fringe pattern phase extraction. However, due to the ill-posed problem of orthogonalization of a single frame fringe pattern, the development of an analytical method for fringe pattern orthogonalizing is full of challenges. In recent years, researchers have demonstrated that deep learning is a powerful machine learning technique that uses artificial neural networks with deep layers to fit complex mathematical functions, thereby, deep learning provides a promising improvement over classical methods derived from explicit analytical formulations of the forward models. More specifically, deep learning approaches handle problems by searching and establishing sophisticated mapping between the input and the target data owing to the powerful computation capability, and therefore may provide a new solution for the phase demodulation of low-frequency fringe pattern. Inspired by recent successful artificial intelligence-based optical imaging applications, in this paper, we propose to utilize the deep learning to solve this problem of under sampling. This paper shows the new phase retrieval method based on deep learning can effectively improve performance and enable new functionalities for fringe profilometry. In the proposed network, the Generative Adversarial Nets areused to generate digitally the phase shifting of original image by combining the prior knowledge of network and fringe pattern denoising normalization. After training on labeled image pairs, the proposed method successfully implemente the desired phase-shifting fringes pattern, which can be viewed as the orthogonal transformation of a fringe pattern. With this Orthogonal transformation network, the wrapped phase can be extracted easily if the sampled fringes pattern is normalized using a trained deep neural network. The validity of the proposed Orthogonal transformation network is demonstrated on both the simulated and experimentally obtained fringe patterns. We also perform a comparative analysis of the proposed and existing approaches. Herein, we conducted fringe pattern denoising-normalization by using a deep-learning-based method developed because of its high-quality reconstruction ability. Thereafter, we input the normalized FP into the proposed Hilbert transformation network to perform Hilbert transform. We demonstrated our approach on both an open and a closed fringe pattern. Indeed, owing to local phase-sign ambiguity, the processed results show that the unwrapped phase map cannot be reconstructed adequately from the existing D4-PS wrapped map, even for a plane. Further, the reference phase from the proposed method is compared with the phase obtained by the multiple-frame high precision phase shift algorithm. Experimental results show that the proposed Orthogonal transformation network can provide a simple and robust solution for optical phase extraction from a single fringe pattern with phase error distribution within 0.05 rad and, therefore, make it allow for paving a new way to measure object 3D profilometry in a transient situation. © 2023 Chinese Optical Society. All rights reserved.
  Accession Number: 20231713946066
• Record 305 of
  
  Title:Analysis of GEO Space Debris Detection Based on Near-GEO Orbit RPO
  
  Author(s):Cui, Kai(1,2); Wang, Feng(1); She, Wen-Ji(1,2); Liu, Zhao-Hui(1,2); Li, Zhi-Guo(1,2); Chen, Rong-Li(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12617  Issue: null  Article Number: 126174Q  DOI: 10.1117/12.2666383  Published: 2023  
  Abstract:The America and Russia set their new space surveillance and detection equipment s to the near GEO orbit, and frequently conducted rendezvous and proximity operations(RPO) tests, which may pose great threats to our effect in protecting the precious GEO satellite assets. But the satellites‟ operator schema, the satellites‟ on-orbit status modes were kept secret by the owners, it was difficult for others to acquire detailed information. Firstly both the America and Russia space surveillance system capacities were investigated and summarized. Secondly, taking the distribution characteristics of GEO debris in mind, simulations were conducted based on the near GEO orbit dynamics and few satellite orbit data, to deduce the satellites trace during the valid TLE intervals. The accuracy verification was checked by the "classified" information disclosed mutually by the America and Russia. Finally, the similarities and differences between the American and Russian near GEO satellites were summarized, and suggestions were towed out when using the near-GEO orbit. According to the suggestion, for a near GEO surveillance equipment, it was proper to take enough flue to pushing themselves for more than 2000km, and was better to satay in every near-GEO orbit for more than 20 days when performing the RPO tests. © 2023 SPIE.
  Accession Number: 20232114130500
• Record 306 of
  
  Title:Design of Wide-range and Multi-spectral TDI-CMOS Imaging System
  
  Author(s):Yang, Yang(1,2); Bo, Zhu(1); Hong, Wang(1); Pei, Yao(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12557  Issue: null  Article Number: 125571J  DOI: 10.1117/12.2651685  Published: 2023  
  Abstract:As the need for image resolution, transmission rate, and integration rises in space remote sensing applications, the charge accumulation-based TDI-CMOS sensor devices evolve fast. This study proposes a TDI-CMOS imaging system based on FPGA to answer the challenge of high-resolution, wide-format multispectral imaging. First, the device selection and stitching design ideas are clarified based on the index requirements of the imaging system; second, the design techniques of the TDI-CMOS imaging system are emphasized, and the implementation methods of critical technologies such as TDI-CMOS timing drive, register configuration, P-spectrum, and B-spectrum image data training, and high-speed data interface design of the imaging system are illustrated; third, the relevant experimental work is described. In conclusion, the experimental work is described, and the experimental findings are examined and interpreted. The experimental findings demonstrate that the imaging system has a signal-to-noise ratio of 45 dB for P-spectrum and 55 dB for B-spectrum and that the resolution of picture elements is 8288 columns for P-spectrum and 2072 columns for B-spectrum. © 2023 SPIE.
  Accession Number: 20230813600606
• Record 307 of
  
  Title:Optimization of polarization parameters for an LCVR polarization spectrometer under non-oversampling
  
  Author(s):Chang, Lingying(1); Wang, Guanru(1); Wang, Xinyou(1); Qiu, Yuehong(2); Chen, Kui(1); Liang, Chi(1)
  Source: Applied Optics  Volume: 62  Issue: 16  Article Number: null  DOI: 10.1364/AO.486941  Published: June 1, 2023  
  Abstract:The spectral polarization measurement can obtain not only the spectral information of the target but also its polarization information, which can improve the detection and identification of the measured target. In the polarization spectrometer based on a liquid crystal variable retarder (LCVR) and acousto-optic tunable filter (AOTF), the LCVR is a core device for achieving fast and high-precision polarization detection. The AOTF is a new, to the best of our knowledge, filter device for spectral tuning. To reduce the sensitivity of an LCVR-based Stokes polarization spectrometer system to errors and Gaussian noise, and to maintain the advantage of fast electrical tuning of the system for spectral polarization detection, the phase retardation and azimuth angle of the polarization device LCVR is calculated and analyzed optimally under the minimum number of samplesN=4 of the Stokes vector measurement method in this paper. The optimization algorithm considers the constraints, such as the number of types of LCVR phase retardation and the number of adjustments, and the azimuth and phase retardation to be optimized are searched for optimality step by step. The simulation results showthat the number of adjustments of the phase retardation δ of LCVRs is only three times when four Stokes parameters are obtained. The LCVRs' number of species is four kinds (2×2). The condition number of the optimized measurement matrix is 1.742, which converges to the ideal condition number, the optimal azimuth angle (θ1; θ2) is (18.9°, 41.9°), and the optimal phase retardation δ is (179.9°, 156.6°, 0.4°, 46.3°). Its corresponding tetrahedral volume is closer to the ideal value. The optimized system is less sensitive to errors andGaussian noise. ©2023 Optica Publishing Group.
  Accession Number: 20232514254024
• Record 308 of
  
  Title:Optical Design of Active Zoom Front System for AOTF Imaging Spectrometer
  
  Author(s):Chang, Lingying(1); Wang, Xinyou(1); Qiu, Yuehong(2); Wang, Guanru(1); Shi, Haonan(1); Liang, Chi(1); Chen, Kui(1)
  Source: Guangxue Xuebao/Acta Optica Sinica  Volume: 43  Issue: 19  Article Number: 1911005  DOI: 10.3788/AOS230664  Published: 2023  
  Abstract:Objective The acousto-optic tunable filter (AOTF) spectrometer can simultaneously acquire the spatial image and spectral information of the detection target, featuring small size, light weight, and flexible selection of central wavelength. The optical system is an essential part of the information obtained by the AOTF imaging spectrometer, and its design scheme and imaging quality can affect the instrument's performance. The zoom system has continuously variable focal lengths. A suitable zoom system can effectively expand the imaging function of the AOTF spectrometer and realize continuous detection, tracking, recognition, and collimation of the target object. The zoom optics of current AOTF spectrometers is mostly mechanical zoom. The mechanical zoom system can modify the focal length only by changing the distance between the components. In contrast, the active zoom system without moving parts can adjust the focus by controlling the changes in curvature and refractive index of the active optical elements. In this study, we propose a design scheme of a combined zoom optical system of AOTF imaging spectrometer, which consists of an active zoom front optical system and a projection system with arbitrary magnification (N) to achieve a wide range of zoom, and the simulation design of active zoom front system is completed. Methods First, the structure and working principle of the AOTF imaging spectrometer are investigated to determine the optical system design scheme, and the design theory of the off-axis three-mirror active zoom optical system is studied in detail to determine the initial structure of the zoom front system. Then, the off-axis field of view (FOV), eccentricity, and tilt of the mirror are added to remove the central light obstruction, which provides more possibilities for the spatial layout of each component. It tends to be coaxial after optimization, and the mirror must be constrained in the tilt and processed by decentration by using the @JMRCC macro function. After that, a progressive approximation is used to implement the continuous zoom function of the front optical system. Starting from the calculation solution of the initial structure at the system's short focus, medium focus, and long focus, the optimization criteria of node addressing and synchronous optimization alternating cycles are used to optimize optical structures at all focal lengths within the zoom range. In addition, the front system is an image space telecentric optical structure, which can effectively reduce the extra aberration caused by the diffraction in AOTF, eliminate parallax, and increase the convenience for the subsequent connection of the projection system and the processing of the system. Last, the linear astigmatism of the TMA is eliminated effectively by debugging the parameters of the incident angle and mirror spacing, and the off-axis aberration of the system is balanced and corrected by adding aspheric surfaces, which are based on even power series polynomials with rotational symmetry, and the design of the system tends to be symmetrical as much as possible control the system distortion problem. Results and Discussions The active zoom front system adopts Cook-TMA with no intermediate image plane based on a variable curvature mirror (VCM), which changes the radius of curvature of the mirror to achieve zoom function (Fig. 5). The maximum central deformations of the mirrors are 44. 2 μm, 73 μm, and 603 μm, respectively. The variations of mirror spacing caused by the deformation of mirrors are 0. 029% (between primary and secondary mirror) and 0. 048% (between secondary and third mirror), and the accuracy of surface shape is better than 0. 0556λ. In the process of system zoom, the mirror curvature radius and focal length are continuously changed, and the zoom curve is smooth without jumping value (Fig. 6). Three mirrors use 8th high-order aspheric surfaces, and coefficients are unchanged during the zoom process. The system is the image-side telecentric structure, and the stop is located in the secondary mirror with a small size, light weight, and compact structure. The results of the design in Code V show that the modulation transfer function (MTF) of zoom front system is greater than 0. 68@34 lp/mm on short focal length, 0. 62@34 lp/mm on middle one, and 0. 45@34 lp/mm on long one with 260-520 mm zoom range and 0. 5-1. 5 μm spectral region (Fig. 7), and root mean square (RMS) radius is less than 0. 193 μm at the short focus, 0. 196 μm at the middle focus, and 0. 345 μm at the long focus (Fig. 8). Conclusions In the present study, a design scheme of a combined zoom optical system for an AOTF imaging spectrometer is presented, which uses a combination of the active front zoom system with different magnifications of the projection system to obtain a larger zoom range, and a design example of a front zoom optical system for AOTF imaging spectrometer is provided. It uses the off-axis method of the coaxial system and the progressive approximation method to realize the off-axis three-mirror active continuous zoom optical system. The system is an image-side telecentric structure, which can effectively increase the convenience for the subsequent connection of the projection system and the processing of the system. The optical system has a working band of 0. 5-1. 7 μm, a zoom range of 260-520 mm, a smooth zoom curve, and a stable image plane with realizable parameters of the VCM. The simulation result shows that the MTF is greater than 0. 45@34 lp/mm, and the RMS radius is less than 0. 345 μm in the full field. The system has a compact structure, with the characteristic of full-electric tuning, fast response speed, small size, and light weight, which can be flexibly applied to a variety of detection scenarios. © 2023 Chinese Optical Society. All rights reserved.
  Accession Number: 20234815124021
• Record 309 of
  
  Title:Sensitivity analysis of pointing error sources for periscope terminals
  
  Author(s):Leyi, Xi(1,2); Junfeng, Han(1,2)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12617  Issue: null  Article Number: 126175R  DOI: 10.1117/12.2666613  Published: 2023  
  Abstract:Aiming at the deviation of the actual light emission direction of the periscope terminal system from the theoretical light emission direction, the optical axis pointing model of the periscope laser communication terminal was established based on the multi-body system theory, and the influence of the mechanical axis system error and the optical axis system error on the pointing model was analyzed, and through the analysis of the sensitivity of the pointing error factors, the error with the greatest influence on the final apparent axis error was obtained as the elevation axis system error. followed by the slope angle error and wedge angle error of the azimuth 45° plane mirror and azimuth axis system error, which provides a basis for the correction of pointing errors. © 2023 SPIE.
  Accession Number: 20232114130526
• Record 310 of
  
  Title:Multispectral image registration parameter calibration method based on pyramid mixture model
  
  Author(s):Gao, Xingli(1,2); Xue, Bin(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12558  Issue: null  Article Number: 125580E  DOI: 10.1117/12.2651499  Published: 2023  
  Abstract:With unique properties, multispectral cameras have become a hot research direction in recent years. In our country's major space mission "Mars Exploration Project", the multispectral camera was mounted on the "Zhu Rong"rover as an important payload to complete a number of exploration missions. Due to the optical structure of the multispectral camera and other reasons, there are often deviations such as rotation, scale change, and displacement between the images of each channel. For multispectral images, there may be huge differences between the image grayscales of different channels. For the same target subject, the local grayscale contrast may even be opposite. Therefore, the conventional image registration method is difficult to solve the alignment issue between the subjects in each channel. In this paper, a calibration method based on a pyramid mixture model of the circular templet is proposed, and a set of accurate calibration parameters is obtained by using the templet images, so as to complete the channel registration of the Mars multispectral image. At the same time, based on the particularity of the template images, an objective evaluation criterion of geometric calibration is proposed. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20230713574400
• Record 311 of
  
  Title:Research on nonlinear relationship between rotation speed and material removal in wheel polishing technology
  
  Author(s):Yao, Yongsheng(1,2); Li, Qixin(1); Jiang, Xiangmin(1); Ding, Jiaoteng(1); Ma, Zhen(1); Fan, Xuewu(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12507  Issue: null  Article Number: 125072E  DOI: 10.1117/12.2656447  Published: 2023  
  Abstract:The classical Preston equation considers that the material removal is linearly related to time, velocity, and pressure. However, in the wheel polishing technology, it is found through experiments that there is a nonlinear relationship between the rotational speed of the polishing wheel and the amount of material removed. In order to accurately control the material removal in the polishing wheel variable speed machining strategy, it is necessary to modify the classical Preston equation. In this paper, the control variable method is used to carry out the sampling experiment: the time and pressure are set as fixed values, and the polishing wheel speed is set as a variable and the value is between 0-4rps. Then the data points were analyzed and a least squares fit was used to obtain a non-linear function between the rotational speed of the polishing wheel and the amount of material removed. Finally, the classical Preston equation is modified to obtain the removal equation suitable for the variable speed machining strategy. © 2023 SPIE.
  Accession Number: 20230613537976
• Record 312 of
  
  Title:Design and tolerance analysis of multispectral infrared off-axis three mirror optical system
  
  Author(s):Chenfeng, Wang(1,2); Weiguo, Lu(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12617  Issue: null  Article Number: 126175Y  DOI: 10.1117/12.2666631  Published: 2023  
  Abstract:In the field of infrared detection, as the application scenarios become more and more complex, the infrared optical system of a single band is limited by the impact of the detection environment, resulting in too little information received, which can no longer meet the detection requirements. Multispectral detection becomes the future research hotspots of such optical systems. Taken advantage of the basic principle of the Gaussian optics and the primary aberration theory, an off-axis three mirror optical system is devised to avoid the central occlusion and improve the energy utilization. The simulation results show that the full field modulation transfer function at the spatial frequency of 20lp/mm in the 4.2~4.45μm band is greater than 0.6, and the MTF of 20lp/mm in the 5.8~7.3μm band is greater than 0.5. In addition, reasonable allocation of system tolerance will greatly affect the imaging capability of the system. Using tolerance sensitivity analysis and inversion sensitivity analysis, calculate the impact of each tolerance on the imaging performance of the system, and reasonably allocate the tolerance. After simulation analysis, the MTF of the system is greater than 0.4 according to the given common error processing and assembly. © 2023 SPIE.
  Accession Number: 20232114130633