Journals >Optics and Precision Engineering
Contents
2024
Volume: 32 Issue 15
11 Article(s)
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[in Chinese]
Modeling of removal function and optimization of process parameters for robotic polishing M-ZnS
Yikai ZANG, Beibei ZHU, Lin QIN, Yao SHANG, Junhao SHANG, Zhongdi SHE, Xiao CHEN, Junfeng XIAO, and Jianfeng XU
To study and optimize the material removal model for robotic polishing of M-ZnS and enhance the precision and cost-effectiveness of manufacturing M-ZnS optical components, the material removal model is refined using the finite element method and numerical simulation. A pressure field distribution model for a 10 mm asphTo study and optimize the material removal model for robotic polishing of M-ZnS and enhance the precision and cost-effectiveness of manufacturing M-ZnS optical components, the material removal model is refined using the finite element method and numerical simulation. A pressure field distribution model for a 10 mm asphalt polishing disc is developed, and the pressure distribution function is determined through curve fitting. The accuracy of the adjusted removal function model is verified with a less than 8% deviation when comparing simulation and experimental data. The polishing process parameters are optimized using a one-factor experimental method, suggesting a pressure range of 0.12 to 0.18 MPa and spindle speed ratios of 200/-10 to 200/-50 r/min for 10 mm discs. These optimizations were applied to polish 100 mm M-ZnS planar optical elements. Post-polishing, the surface quality significantly improved within 80.39 min; the M-ZnS transitioned from light yellow to transparent, face shape PV decreased from 0.668 μm to 0.229 μm, with a 65% improvement, and surface roughness Sa went from 7.911 nm to 2.472 nm, with a 68% enhancement. Thus, robotic polishing proves vital for efficient, high-quality finishing of M-ZnS optical components..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2387 (2024)
Research progress of parallel coordinate measuring machine
Kai OUYANG, Rao FU, Long YANG, and Penghao HU
Parallel mechanisms offer benefits like high stiffness, strong load capacity, excellent dynamic performance, and error averaging between branches, making them popular in robotics and machine tools. In contrast, serial coordinate measuring machines, such as portable versions, suffer from error accumulation. Due to the aParallel mechanisms offer benefits like high stiffness, strong load capacity, excellent dynamic performance, and error averaging between branches, making them popular in robotics and machine tools. In contrast, serial coordinate measuring machines, such as portable versions, suffer from error accumulation. Due to the advantages of parallel mechanisms, parallel coordinate measuring machines have rapidly advanced over the past twenty years. Current research covers their mechanisms, kinematics, dynamics, mechanical performance, and control strategies. Key issues in current research are identified, with proposed solutions and ideas. Future development trends in this field are also discussed..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2401 (2024)
Vertical clamping deformation analysis and validation of 300 mm wafer warpage detection
Yibo ZHANG, Xinxin KONG, Sizepeng ZHAO, Jingang JIA, Dehuai JIANG, Jiahui SONG, and Zhou WU
To address the challenges of detecting additional deformation errors caused by external forces during wafer warpage detection-errors that are difficult to eliminate and quantify-this paper proposes an improved vertical automatic clamping solution for rapid and high-precision industrial wafer warpage detection. By leverTo address the challenges of detecting additional deformation errors caused by external forces during wafer warpage detection-errors that are difficult to eliminate and quantify-this paper proposes an improved vertical automatic clamping solution for rapid and high-precision industrial wafer warpage detection. By leveraging theoretical analysis, finite element simulations, and wafer warpage characterization methods, the paper introduces an analytical approach to wafer clamping design, elucidating the relationship between key design parameters and additional wafer warpage. The study achieves forward design of critical parameters for the vertical clamping mechanism, with validation experiments for production and repeated clamping based on the design results. Analysis and experimental outcomes demonstrate that vertical clamping can ensure the additional bow of a 300 mm single-crystal silicon wafer does not exceed 70 nm, and the warp remains under 1 000 nm, provided that the wafer attitude tilt angle is less than 0.02°, the bottom fixed constraint position slope angle is 35°±1°, and the clamping force is not more than 2 N with an angle not exceeding 2° from the vertical direction. This research offers practical guidance for developing a high-precision geometric profiling instrument for 300 mm wafers and large-size optical component clamping..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2418 (2024)
[in Chinese]
Polarization-tunable shearing interferometry method for real-time reconstruction of large aberration wavefronts
Dian BIAN, Yating LUO, Dengfeng HOU, and Zai LUO
This paper introduces a polarization-based single-frame wavefront reconstruction method using a compact and stable shear interferometry structure for real-time measurement of large aberration wavefronts. This approach overcomes the need for multiple images in traditional lateral shear interferometry, allowing real-timeThis paper introduces a polarization-based single-frame wavefront reconstruction method using a compact and stable shear interferometry structure for real-time measurement of large aberration wavefronts. This approach overcomes the need for multiple images in traditional lateral shear interferometry, allowing real-time reconstruction of large aberration samples. The method is theoretically supported by simulations based on an infinite conjugate model, and computational reconstruction of large aberration wavefront samples confirms the algorithm's feasibility. A dual-plane mirror tunable shear interferometry structure, combined with polarization devices, is experimentally validated using a resolution target, achieving real-time fringe separation and wavefront reconstruction. The results show high accuracy with a root mean square error of 60 nm and improved runtime of 0.11 s. The proposed design and algorithm eliminate the need for multiple image reconstruction, simplify lateral shear interferometry, improve detection efficiency of three-dimensional macro and micro samples, and have potential applications in optical quantitative coherent interferometric measurement..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2325 (2024)
Flexible ultrablack surface with high absorption performance
Jiazheng WU, Yang AN, and Wei LI
Ultrablack surfaces are vital in thermal radiation and other fields. This study introduces a cost-effective method to create ultrablack surfaces with broad spectral and high absorption traits using femtosecond laser and reverse molding technology. It investigates the impact of laser parameters on the morphology and sizUltrablack surfaces are vital in thermal radiation and other fields. This study introduces a cost-effective method to create ultrablack surfaces with broad spectral and high absorption traits using femtosecond laser and reverse molding technology. It investigates the impact of laser parameters on the morphology and size of copper surface microstructures, determining optimal parameters for periodic microstructure processing. The research develops a process flow that integrates secondary molds with black paint substrates, achieving a flexible ultrablack surface with high absorption across the solar spectrum. An innovative solar absorber design using the ultrablack surface and ITO transparent glass is tested through outdoor experiments. The results demonstrate absorption rates of up to 98.3% for normal incidence and over 90% at a 70° angle. The solar absorber with ITO glass can increase the device temperature by up to 4 ℃. The process is simple, cost-effective, and suitable for large-scale application due to its flexible substrate..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2334 (2024)
Fiber optic temperature sensor based on enhanced harmonic vernier effect
Zixi LIN, Yuting LI, Yuqiang YANG, Yitong LI, and Yuying ZHANG
The proposed temperature sensor utilizes the enhanced harmonic vernier effect in an optical fiber system, combining an optical fiber Sagnac interferometer (SI) with a Fabry-Perot interferometer (FPI). By aligning the FPI's free spectral range as a multiple of the SI's, with opposite temperature responses, the eThe proposed temperature sensor utilizes the enhanced harmonic vernier effect in an optical fiber system, combining an optical fiber Sagnac interferometer (SI) with a Fabry-Perot interferometer (FPI). By aligning the FPI's free spectral range as a multiple of the SI's, with opposite temperature responses, the enhanced harmonic vernier effect is achieved. Experiments show that this effect and the enhanced normal vernier effect have comparable temperature sensitivity, being 28.7 and 16.9 times greater than those of single FPI and SI, respectively. In addition, the magnification of the enhanced harmonic vernier is 3.4 and 1.8 times that of the normal harmonic vernier. However, the detuning of the Panda fiber length for the enhanced harmonic vernier effect is significantly larger than for the enhanced normal vernier effect, with detuning increasing with order. The enhanced harmonic vernier's magnification is also easier to control at higher orders. The sensor demonstrates high sensitivity, excellent stability, and low preparation cost, offering promising prospects for practical applications..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2344 (2024)
Image measurement of shock wave flow field at outlet of large diameter explosion shock tube
Xing ZHENG, Haiying HUANG, Yongjian MAO, Jun ZHANG, and Dong ZHOU
To capture schlieren images of explosion shock waves over a large field of view and analyze the flow field evolution after shock wave interaction with a model, a reflective high-speed schlieren measurement technique based on focused schlieren was developed. The system uses a laser source and high reflective film for inTo capture schlieren images of explosion shock waves over a large field of view and analyze the flow field evolution after shock wave interaction with a model, a reflective high-speed schlieren measurement technique based on focused schlieren was developed. The system uses a laser source and high reflective film for input. By simplifying the knife-edge grid design, the shock wave flow field evolution at the outlet of a long-distance, large-aperture explosion shock tube and its high-resolution interaction with a solid model are achieved. At a distance of over 80 m, shock wave characteristics were obtained from a large-caliber, high-yield explosion shock tube with a 6 m×3 m field of view, along with high temporal and spatial resolution images and state data regarding interactions with solids. The study shows that the designed focused schlieren system is simpler, more feasible, and offers a longer test distance and wider field of view than traditional systems. By altering the light source input, the benefits of a laser source for long-distance imaging are explored. The interaction between the shock wave front and the solid model reveals the formation, evolution, and flow state of the shock wave on the model. These measurements provide visual data to support the evaluation and response analysis of weapons and equipment subjected to shock waves..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2355 (2024)
Aperture stop diffraction effect of solar irradiance measurement
Jieling YU, Hang DONG, Xiaolong YI, Yuchen LIN, Silong WANG, Qingxiang MIAO, Rui SUN, Zhanpeng GAO, Wei FANG, and Xin YE
To address the current reliance on theoretical calculations for evaluating the diffraction effects of aperture stops in irradiance measurement, an experimental method to detect diaphragm diffraction effects was developed. This aims to correct aperture stop diffraction and enhance total solar irradiance measurement accuTo address the current reliance on theoretical calculations for evaluating the diffraction effects of aperture stops in irradiance measurement, an experimental method to detect diaphragm diffraction effects was developed. This aims to correct aperture stop diffraction and enhance total solar irradiance measurement accuracy. Utilizing dark-field imaging and Fraunhofer far-field diffraction theory, a detection method was designed and tested. By calibrating detector linearity, correcting background signals, and analyzing diffraction image data, a data correction process was established. This process determined the solar absolute radiometer diffraction effect value at the aperture stop's front structure and assessed the experimental uncertainty. The experiment found a diffraction effect value of 8.81×10-4 with a total uncertainty of 6.49%. These findings provide a crucial technical foundation for accurately correcting diffraction effects in China's next-generation Fengyun meteorological satellites' solar radiation monitors, enabling precise total solar irradiance measurements..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2363 (2024)
Parallelism measurement and trajectory planning of multi-channel double crystal monochromator
Haolin LU, Maomao LIU, Siyu HE, Zhao FENG, Xiaowei ZHANG, Lin TANG, Jianhua HE, and Xiaohui XIAO
To address parallelism error compensation in a dual-rotation multi-channel double crystal monochromator (DCM), we propose a method using an autocollimator to measure the quasi-static parallelism of diffraction surfaces and an S-curve trajectory planning method. First, we analyze the structure and motion of the monochroTo address parallelism error compensation in a dual-rotation multi-channel double crystal monochromator (DCM), we propose a method using an autocollimator to measure the quasi-static parallelism of diffraction surfaces and an S-curve trajectory planning method. First, we analyze the structure and motion of the monochromator. Then, we present a measurement system framework using the autocollimator. We also propose an S-curve trajectory planning algorithm to optimize the motion trajectory based on parallelism measurements. Finally, experiments on the constructed platform show that the measurement system achieves a 0.5" resolution, with crystal angle transitions varying by hundreds of arcseconds. The S-curve planning algorithm reduces trajectory tracking error by 58.7% and 63.9% compared to a 5th order polynomial and unplanned trajectories, respectively, with a 6.1" tracking error. These results confirm the method's efficacy in enhancing the performance of the monochromator..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2374 (2024)
[in Chinese]
Digital diffraction method for single retinal image enhancement
Shuhe ZHANG, and Liangcai CAO
Enhancing RGB retinal images is vital for retinopathy detection and monitoring, but issues like uneven intensity often degrade visual quality. This research introduces a digital diffraction-based method to improve uneven intensity and contrast while preserving color naturalness. Initially, the retinal image is converteEnhancing RGB retinal images is vital for retinopathy detection and monitoring, but issues like uneven intensity often degrade visual quality. This research introduces a digital diffraction-based method to improve uneven intensity and contrast while preserving color naturalness. Initially, the retinal image is converted to LCH color space, where intensity correction is applied to the L channel, treated as an optical field. A digital propagation with a specific kernel estimates the intensity pattern, which, when subtracted, yields a corrected L channel. Multi-image fusion with varied kernels then ensures uniform intensity. The same process corrects the C channel for color accuracy. Tested on 1 200 Messidor dataset images, this method surpasses Gamma correction and Retinex methods, enhancing contrast and uniformity by 3%-4% when combined with CLAHE. The improved contrast aids applications like retinopathy detection and blood vessel segmentation..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2429 (2024)
Visible-polarized image fusion for nighttime dispersal of mines
Kangyu SHEN, Bolun CUI, Qifeng LYU, and Chi WANG
To address the challenge of weak spectral intensity differences between dispersed mine targets and the surrounding ground in low light conditions at night, an end-to-end unsupervised visible-polarized image fusion enhancement algorithm is explored. This algorithm uses the polarization characteristics of scattered minesTo address the challenge of weak spectral intensity differences between dispersed mine targets and the surrounding ground in low light conditions at night, an end-to-end unsupervised visible-polarized image fusion enhancement algorithm is explored. This algorithm uses the polarization characteristics of scattered mines to enhance nighttime mine targets while preserving scene texture details. The fusion algorithm network consists of a feature extraction module, a feature fusion module, and an image reconstruction module. A hybrid attention mechanism is incorporated to improve the network's ability to extract significant information from the feature tensor. Additionally, a loss function based on pixel content distribution is designed to ensure the fused image retains prominent pixel features from the source image, enabling end-to-end network output. For the nighttime landmine scattering dataset, evaluations using seven mainstream image fusion methods showed superior performance across eight metrics, including SSIM and VIF. The fusion-enhanced image in the YOLOv5 model surpassed the intensity image in landmine detection tasks. This model is state-of-the-art and positively impacts subsequent mine detection missions..
Optics and Precision Engineering
- Publication Date: Aug. 10, 2024
- Vol. 32, Issue 15, 2439 (2024)
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