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Error analysis of surface-distribution and non-deformation of fluorescent beads for the IC-GN2 DVC algorithm Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-21 Shihai Lan; Yue Gao; Xiaohai Xu; Yong Su; Yongman Liu; Chuanbiao Bai; Shangquan Wu; Qingchuan Zhang
Digital volume correlation (DVC) method is extensively used for the internal displacement measurement. In biomechanical experiments, fluorescent beads are used, instead of traditional speckles (or microstructure of materials), as the information feature of the volume image for DVC algorithm. The traditional experimental method and DVC algorithm, together, provide an effective measurement method for
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Optical color image encryption based on fingerprint key and phase-shifting digital holography Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-21 Yonggang Su; Wenjun Xu; Tianlun Li; Jie Zhao; Shuaiqi Liu
In this paper, an optical color image encryption scheme based on fingerprint key and three-step phase-shifting digital holography is proposed. In the proposed encryption scheme, the fingerprint is served as secret key directly, and the random phase masks generated from the fingerprint using secure hash algorithm and chaotic map are just used as interim variables. With the help of the fingerprint-based
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Spatial resolution of light field sectioning pyrometry for flame temperature measurement Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-21 Yudong Liu; Mingjuan Zhu; Tianxiang Wang; Gang Lei; Md. Moinul Hossain; Biao Zhang; Jian Li; Chuanlong Xu
The light field sectioning pyrometry (LFSP) has proven a significant advancement for in-situ measurement of flame temperature through a single light field camera. However, the spatial resolution of LFSP is limited, which severely inhibits the measurement accuracy. This paper aims to evaluate the spatial resolution of LFSP for flame temperature measurement quantitatively. A theoretical model of the
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Development and analysis of surface plasmon resonance based refractive index sensor for pregnancy testing Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-22 Sumaiya Akhtar Mitu; Kawsar Ahmed; Fahad Ahmed Al Zahrani; Amit Grover; Murugan Senthil Mani Rajan; Mohammad Ali Moni
In the proposed work, a two-dimensional photonic crystal fiber (PCF) based on the surface plasmon resonance (SPR) refractive index sensor has been demonstrated and designed which is so much helpful to gain a better sensitivity response in urine observation. In order to detect the pregnancy, the simulation and analysis have been performed in both normal and pregnant urine with the effective refractive
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Extended focused imaging in microscopy using structure tensor and guided filtering Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-22 Zhenbo Ren; Peiyan Guan; Edmund Y. Lam; Jianlin Zhao
The limited depth-of-field (DOF) in optical microscopic imaging systems prevents them from capturing an entirely focused images when the imaged scene is thick and covers a wide range of depth. Specimens lying outside the DOF is defocused and thus blurred, hindering the subsequent observation and analysis. Extended focused imaging aims at yielding a single all-in-focus image by combining the in-focus
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Optical design of a high-resolution spectrometer with a wide field of view Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-22 Chaobin Zeng; Yan Han; Bin Liu; Peng Sun; XianJing Li; Ping Chen
The currently available area array imaging spectrometer fails to provide high spectral resolution and fast imaging under a wide field of view (FOV). Therefore, this study proposes an integral field imaging spectrometer (IFIS) that uses an image-space telecentric lens (ISTL), a mask, and lenslet array (MLA) as the front structure of the system. The influence of their structural parameters on the optical
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Single pixel 3D imaging with phase-shifting fringe projection Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-20 Yanyang Ma; Yongkai Yin; Shan Jiang; Xianye Li; Feng Huang; Baoqing Sun
Single pixel three-dimensional (3D) imaging technique has attracted lots of attention owing to its potential capability of working in a wide waveband. In this work, the single pixel 3D imaging is realized with the assistance of phase-shifting fringe projection. The deformed fringe images are recorded with the passive single pixel imaging technique, and the 3D information of the object is calculated
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Design and implementation of photoacoustic based beam dump-average optical power meter for fast and ultrafast lasers Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-19 H.S. Ayoub; Ashraf F. El-Sherif; Sana M.A. Maize; Y.H. Elbashar
We reported a new method for measuring the optical power of fast and ultrafast laser pulses. This type of measurements usually encounters some technical difficulties in field of experimental practice. The method is based on investigating the laser-induced photoacoustics (PA) inside a non- lambertian integrating sphere made of stainless steel. The measured laser beam is introduced inside the sphere
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Self-reference dispersion correction for chromatic confocal displacement measurement Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-20 Jiao Bai; Xinghui Li; Xiaohao Wang; Jianjian Wang; Kai Ni; Qian Zhou
Dispersion is a very common phenomenon in the broadband optical systems. Chromatic confocal technology uses the chromatic aberration of lens to decode the axial displacement of the sample surface by the focus-wavelength of the reflected spectrum. Dispersion characters of the light source and sample surface greatly influence the reflected spectrum except the useful chromatic aberration, leading to focus-wavelength
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Real-time measurements of phase steps out-of-range (0,2π) by a dynamic self-calibrating generalized phase-shifting algorithm Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-20 Juan Carlos Gomez-Conde; Cruz Meneses-Fabian
Recently, a method for measuring phase steps in real-time from a dynamic interferogram within the range (0,2π) has been presented. It was named Dynamic Volume Enclosed by a Surface (DVES) method and was built on a very well known algorithm of type self-calibrating generalized phase-shifting interferometry relied on geometric concept of volume enclosed by a surface (VES), which is enough fast, and accurate
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High definition images transmission through single multimode fiber using deep learning and simulation speckles Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-13 Leihong Zhang; Runchu Xu; Hualong Ye; Kaiming Wang; Banglian Xu; Dawei Zhang
Multimode fiber (MMF) plays a vital role in promoting the miniaturization of endoscope. However, real-time and high-definition imaging using the MMF that remains a challenging research. Traditional phase compensation and transmission matrix methods are affected by fiber shape and optical devices, which results in low imaging rate and accuracy. Deep learning can be used to construct the inverse transformation
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High imaging quality of Fourier single pixel imaging based on generative adversarial networks at low sampling rate Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-13 Xu Yang; Pengfei Jiang; Mingfeng Jiang; Lu Xu; Long Wu; Chenghua Yang; Wei Zhang; Jianlong Zhang; Yong Zhang
Single pixel imaging is an innovative imaging scheme using active light to obtain spatial information, which has attracted much attention in the computational imaging field. However, for single pixel imaging, it is a great challenge to find an efficient technique to obtain imaging results with high quality under low sampling conditions. In order to solve this problem, a Fourier single pixel imaging
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Measurement of latex microparticle size by dynamic speckle technique Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-09 Luis J. Mendoza-Herrera; Daniel C. Schinca; Lucía B. Scaffardi; Eduardo E. Grumel; Marcelo Trivi
We propose a method for dielectric microparticles size measurement based on the temporal evolution of speckle pattern. We conducted experiments using aqueous suspension of different standard spherical latex particles that span a size range between 5 µm and 100 µm. To analyze the speckle pattern data, we use different and independent qualitative and quantitative algorithms. We built calibration curves
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Motion correction of laser speckle imaging of blood flow by simultaneous imaging of tissue structure and non-rigid registration Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-04 Xiaohu Liu; Jiakai Wei; Liangwei Meng; Weimin Cheng; Xuan Zhu; Jinling Lu; Pengcheng Li
Laser speckle contrast imaging (LSCI) has been widely used for mapping blood flow. LSCI is well known to be highly sensitive to movement artifacts. Previous studies attempted to register the global misalignment by using raw speckle images and rigid registration algorithm. However, it is difficult to correct the local non-rigid motion only by using granular raw speckle images, especially in the tissue
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Concentric circle grids for camera calibration with considering lens distortion Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-04 Lingbin Bu; Hongtao Huo; Xiaoyuan Liu; Fanliang Bu
The accuracy of camera calibration depends significantly on the control point detection which customarily subjects to image noise, distortion and resolution. This paper uses concentric circle grids as the calibration pattern and accordingly proposes a robust and accurate control point detection method for camera calibration. Each set of concentric circles on the grids pattern consists of multiple circles
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Extreme shearography: Development of a high-speed shearography instrument for quantitative surface strain measurements during an impact event Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-04 Andrei G. Anisimov; Roger M. Groves
Monitoring of extreme dynamic loadings on composite materials with high temporal and spatial resolution provides an important insight into the understanding of the material behaviour. Quantitative measurement of the surface strain at the first moments of the impact event may reveal the initiation of the failure mechanisms leading to damage. For this purpose, we developed a shearography instrument for
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Calibration refinement for a fringe projection profilometry system based on plane homography Opt. Laser Eng. (IF 4.273) Pub Date : 2021-01-03 Jian Yu; Feipeng Da
This paper presents a calibration parameters refinement specifically for a fringe projection profilometry system to assure the final accuracy, even when using an imperfect calibration target. Unlike existing camera-projector calibration methods, we arrange a refinement in subsequent process of target measurement. Following the trend of additionally estimating the target’s geometry, a novel formulation
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Linear programming-based reconstruction algorithm for limited angular sparse-view tomography Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-29 Xiongfeng Zhang; Haibo Liu
The reconstruction of high-quality images from limited angular sparse-view tomography data is desired in many fields, including low-dose computed tomography and nondestructive detection. In this study, two regularization terms based on the assumptions of image continuity and nonzero pixels are utilized to reconstruct an image from incomplete data. By transforming the original nonlinear reconstruction
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Accurate and dense point cloud generation for industrial Measurement via target-free photogrammetry Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-26 Nan Ye; Hongyu Zhu; Mingqiang Wei; Liyan Zhang
Industrial photogrammetry systems commonly require multiple coded targets to establish a global coordinate frame for relatively large objects. However, there are many industrial products that do not allow coded targets to be placed on their surfaces. We propose an accurate and dense point cloud generation approach for measuring large-sized, untextured objects. Unlike most existing industrial measurement
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Spot pattern separation in multi-beam laser pointing using a neural network Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-26 Lei Xia; Yuanzhan Hu; Wenyu Chen; Xiaoguang Li
In various laser applications with multiple beams, measuring the pointing errors of different beams is a prerequisite. Normally, this is done by multiple measurements of corresponding laser spots after separating each beam. In this study, a neural network method is utilized to predict the position and angular errors of dual lasers from a single superimposed spot image on a tilted detector, and thus
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Optical phase-shifting methods based on low coherence laser for large aperture Fizeau interferometer Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-25 Xinyu Miao; Yifan Yu; Aobo Li; Jun Ma; Lei Chen; Jianxin Li; Qing Wang; Cong Wei; Rihong Zhu; Caojin Yuan
PZT is commonly used as the phase shifter in interferometric systems with small apertures for decades. However, it becomes more difficult to be applied to the system with large aperture. In this paper, the phase shifting procedure is moved to the source module with a low coherence laser, which makes phase shifting independent of the large interference cavity. The path matching procedure based on intensity
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Fourier ptychographic rapid superresolution imaging via line-scanning microscopy with virtual structural- modulated Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-24 Famin Wang; Yun Xiao; Jiawang Zhao; Yunhai Zhang; Hangfeng Li
In this paper, we proposed a new method that combines virtual structural-modulated (VSM), line-scanning microscopy (LSM) and the Fourier ptychography (FP) algorithm to rapid super-resolution imaging. VSM provides an easy, low-cost and phase-artifact-free strategy to achieve super-resolution imaging. However, the practical application of this method is challenging due to a limited image acquisition
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Laser fabrication of fully printed graphene oxide microsensor Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-23 Xingsheng Wang; Jian Zhang; Xinliang Mei; Bin Xu; Jieliang Miao
Fully printed microsensors are widely used in daily life to monitor various parameters of health, environment, and food, etc. However, the fabrication of fully printed microsensors still suffers from multiple procedures and excessive devices. Herein, a facile approach using combinational laser micromachining techniques with the same laser is developed to fabricate fully printed microsensors. Three
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Removing light interference to improve character recognition rate by using single-pixel imaging Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-23 Xicheng Gao; Huaxia Deng; Mengchao Ma; Qingtian Guan; Qianzhen Sun; Wuhan Si; Xiang Zhong
Optical Character Recognition (OCR), which is generally based on figure recognition, is mainly effective for extracting text from pictures. However, it is a challenge to maintain a high recognition rate without being affected by light interference in a complicated environment. To reduce the light interference for improving the OCR recognition rate, this article proposes a method utilizing single-pixel
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High-speed and high-accuracy fringe projection profilometry without phase unwrapping Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-23 Huaxia Deng; Xing Ling; Yuyu Wang; Pengcheng Yao; Mengchao Ma; Xiang Zhong
High-speed and high-accuracy measurement is the ultimate objective of fringe projection profilometry(FPP). However, improving measurement speed, especially without the reduce of measurement accuracy, poses a great challenge for the development of FPP. In contrast to the existing methods, which typically use phase unwrapping method, this paper proposes a high-speed and high-accuracy FPP without phase
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Novel defocus hologram aberration compensation method in digital holography integrated pathology microscope for label free 3-D imaging Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-23 B. Karthik Goud; S.D.V.S. Jagannadha Raju; K. Divakar Rao
In this paper we report successful integration of digital holography in off- axis transmission configuration into a commercially available pathology microscope (PathologyDHM), where Mach-Zehnder interferometric configuration was achieved in pathology microscope using 1 × 2 single mode fiber coupler and custom built optical modules. A smartphone/webcam positioned at the image plane of the finite conjugate
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The mobile ultrafast high energy laser facility - A new facility for high-intensity atmospheric laser propagation studies Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-23 D. Thul; R. Bernath; N. Bodnar; H. Kerrigan; D. Reyes; J. Peña; P. Roumayah; L. Shah; D. Maukonen; J. Bradford; M. Baudelet; S. Rostami Fairchild; M. Richardson
We present the design, performance, and initial activation of the Mobile Ultrafast High Energy Laser Facility, a 5 TW near-infrared laser source located on a multi-km test range at Kennedy Space Center. The system is compact, readily transportable, and provides a robust, tunable output suitable for long range studies of high intensity laser propagation. The supporting testing infrastructure, which
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Evaluation of pre-determined dilution of high strength steels by the Snapshot method Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-18 Stephanie M. Robertson; Jan Frostevarg; Jonas Näsström; Therese Berndtsson; Alexander F.H. Kaplan
Dilution is an unavoidable consequence of multi-material fusion processing, i.e. welding, cladding etc. In this paper we propose a novel method for controlled dilution experiments, analyzing microstructural trends of steel filler wire diluted with steel base metal. The highlight of this method is the control of processing conditions used to melt a pre-determined dilution of two high strength steels
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Separation detection and correction of mosaic errors in mosaic gratings based on two detection lights with the same diffraction order and different incident angles Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-17 Guojun Yang; Xiangdong Qi; Xiaotao Mi; Shanwen Zhang; Hongzhu Yu; Haili Yu; Xiaotian Li
Grating tiling is an important fabrication technology for large-size gratings. However, when using grating tiling technology to form large-size echelle gratings, the interferometer cannot detect the grating's zero-order diffraction wavefront because the zero-order diffraction light of the echelle grating is weak. This prevents use of the zero-order and non-zero-order diffraction light of the grating
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Imaging mechanism and degradation characteristic analysis of novel rotating synthetic aperture system Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-16 Xiyang Zhi; Shikai Jiang; Lei Zhang; Dawei Wang; Jianming Hu; Jinnan Gong
The Rotating synthetic aperture (RSA) is one of the most promising novel imaging systems to meet the requirements of lightweight and high resolution for optical remote sensing satellites, especially in geostationary orbit. The point spread function (PSF) orientation relative to the observed scene, intentionally changes to measure all spatial frequency information available to a filled circular aperture
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Direct bonding of copper foil and liquid crystal polymer by laser etching and welding Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-16 Le Jia; Haifeng Yang; Yisai Wang; Baocai Zhang; Hao Liu; Jingbin Hao
The reported laser welding of dissimilar materials (metal and plastic) mostly focuses on the optimization of parameters and process, the process is complex and the cost is high. Liquid crystal polymer (LCP) has attracted much attention due to its excellent electrical properties. With the rapid development of information technology, 5G high-frequency communication is gradually emerging. At the same
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Multi-rotation coherent imaging by a phase mask Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-16 Yong Geng; Xiu Wen; Xuyang Zhou; Yutong Li; Jiubin Tan; Weiqiang Ding; Shutian Liu; Zhengjun Liu
A high-efficiency coherent imaging system is designed by using phase modulation. After rotating a known phase mask, three images from rotation modulation are recorded and utilized to accurately reconstruct the complex-value sample. Specially, the system is free from rotation angle calculation, and requires fewer intensity measurements. This method has a superiority in convergence speed and calculation
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Estimating gray intensities for saturated speckle to improve the measurement accuracy of digital image correlation Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-15 Xiaoliang Hu; Zhijiang Xie; Fei Liu
Accuracy of digital image correlation (DIC) is deeply affected by illumination variation, especially the local pixel saturation exists. A simple and efficient gray intensity adjustment strategy based on feature matching and standard DIC method is presented for estimating the intensities of saturated pixels. Principle of the strategy based on surrounding pixels around the saturated pixel and the principle
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Lens-based phase retrieval under spatially partially coherent illumination—Part I: Theory Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-14 Claas Falldorf; Mostafa Agour; Fabian Thiemicke; Ralf B. Bergmann
We present a novel approach of phase retrieval using a 4f-imaging system, for the specific case of spatially partially coherent illumination. The theoretical investigation presented in Part I is based on scalar diffraction theory in combination with a heuristic approach. We find that the intensity of the de-focused speckle fields across the image plane shows sufficient contrast for phase retrieval
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Fiber Optic Shape Sensors: A comprehensive review Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-13 Ignazio Floris; Jose M. Adam; Pedro A. Calderón; Salvador Sales
Fiber Optic Shape Sensing is an innovative Optical Fiber Sensing Technology that uses a fiber optic cable to continuously track the 3D shape and position of a dynamic object (with unknown motion) in real-time without visual contact. This technology offers a valid alternative to existing shape sensing methods, thanks to a combination of advantages (including ease of installation, intrinsic safety, compactness
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Penetration-depth control in a remote laser-welding system based on an optical triangulation loop Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-13 Matjaž Kos; Erih Arko; Hubert Kosler; Matija Jezeršek
Remote laser-welding systems are being used more frequently because of their larger working areas, shorter downtimes and ability to weld different seam types with high accuracy at greater speeds in comparison to conventional welding. Therefore, precise process-monitoring methods are needed in order to achieve weld traceability and good process and quality control to accompany different welding situations
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A compact, low-cost and high sensitive LIF based on pinhole metal-capillary and direct laser-diode excitation Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-12 Weicheng Cai; Hui Huang; Zhibo Yang; Ruichen Shang; Xuejing Li; Chi Ma; Jian Zhao; Pengbo Liu; Jian Wang; Wei Wang
For laser-induced fluorescence (LIF), the SNR and related concentration detectability was severely limited by background signal (noise). Herein, an axial-excitation LIF based on pinhole metal-capillary (PMC) and direct laser-diode excitation was proposed. An overall ~480 fold improvement on SNR was realized, because the laser-sidewall interaction (LSI) and related background signal (noise) can be effectively
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Short U-net model with average pooling based on in-line digital holography for simultaneous restoration of multiple particles Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-11 Wei-Na Li; Ping Su; Jianshe Ma; Xiaohao Wang
We propose a short U-net model with average pooling to restore in-focus images of multiple transparent particles at their ground truth z-positions, while simultaneously removing their zero-order images, conjugate images, defocused images of other particles, and the noise associated with the optical system. Subsequently, we obtain the lateral location and diameter of each particle efficiently, thus
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Shape measurement of a thin glass plate through analyzing dispersion effects in a white-light scanning interferometer Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-10 Songjie Luo; Osami Sasaki; Samuel Choi; Takamasa Suzuki; Ziyang Chen; Jixiong Pu
Utilization of a complex-valued interference signal (CVIS) in a white-light scanning interferometer is a powerful method to measure exactly surface positions of a glass plate. In this method a zero phase position nearest to a maximum amplitude position in the CVIS is a measured surface position. Proportional coefficients that relate the maximum amplitude position and the zero phase position of a rear
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Initial structure of dispersion objective for chromatic confocal sensor based on doublet lens Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-09 Zilong Zhang; Rongsheng Lu
Dispersion objective is the crucial device of chromatic confocal sensor (CCS). The dispersion range and numerical aperture (NA) determine the measurement range and the maximum measurement slope of CCS, respectively. In this paper, we present two kinds of initial structures of dispersion objective for CCS based on doublet lens, which are suitable for the design of dispersion objectives with large dispersion
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Distorted point spread function and image reconstruction for ghost imaging Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-07 Zijie Li; Qing Zhao; Wenlin Gong
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Security analysis and modified attack algorithms for a nonlinear optical cryptosystem based on DRPE Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-07 Phool Singh; Ravi Kumar; A. K Yadav; Kehar Singh
In this paper, security of a nonlinear optical cryptosystem based on double random phase encoding (DRPE) is analyzed. In the cryptosystem, a time-varying nonlinear term is combined with the classical DRPE technique to enhance security. The advantages of the nonlinear term are its easy distribution and no effect on the decrypted image. Also, it is confirmed that the method is resistant to conventional
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Scanning ion beam etching: A method for the fabrication of computer-generated hologram with nanometric accuracy for aspherical testing Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-07 Ruoqiu Wang; Zhiyu Zhang; Yingying Bai; Yanchao Wang; Xiaolin Yin; Lingsheng Kong; Weijie Deng; Donglin Xue; Xuejun Zhang
The phase type computer generated hologram (CGH) plays an important role in aspherical surface optical testing, especially for low reflectivity material mirror surfaces, owing to its high diffractive efficiency. With the increasing demand for high precision CGHs, traditional methods such as reactive ion etching and focusing ion beam, have difficulty realizing the fabrication of a large aperture and
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Optical vortex trajectory of the edge-diffracted single-charged Laguerre-Gaussian beam Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-07 Aleksey V. Chernykh; Nikolay V. Petrov
The paper deals with the edge diffraction of the single charged Laguerre-Gaussian beam outside the waist. Based on the Kirchhoff-Fresnel integral, the behavior of the optical vortex (OV) migration during sequential beam blocking by the straight edge of the screen is performed analytically. Universal combination of the diffracting-beam parameters determining the shape for the OV spiral trajectories
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An anti-noise composite optical fiber vibration sensing System Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-07 Hongyu Yuan; Yu Wang; Rui Zhao; Xin Liu; Qing Bai; Hongjuan Zhang; Yan Gao; Baoquan Jin
In order to eliminate strong ambient noise affecting the detection performance of optical fiber vibration sensing system, a composite system is proposed in this paper, which merges Michelson interferometer (MI) structure, Mach-Zehnder interferometer (MZI) structure and phase-sensitive optical time domain reflector (Φ-OTDR) structure by optical path coupling and wavelength division multiplexing. The
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Characteristics of the holographic diffuser in integral imaging display systems: A quantitative beam analysis approach Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-06 Zhan Yan; Xingpeng Yan; Yingqing Huang; Xiaoyu Jiang; Zhiqiang Yan; Yunpeng Liu; Yan Mao; Qiang Qu; Pei Li
The holographic diffuser plays a significant role in the reconstruction performance of the large-size integral imaging display system. However, the influence of the holographic diffuser on the display quality is seldom theoretically analyzed. In this paper, a quantitative beam analysis approach is proposed, and a diffusing model is established to analyses the influence of the position and diffusing-angle
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An effective coded exposure photography framework using optimal fluttering pattern generation Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-06 Guangmang Cui; Xiaojie Ye; Jufeng Zhao; Liyao Zhu; Ying Chen; Yu Zhang
Motion blurring often occurs during camera imaging process due to the relative motion between the scene and imaging sensor, which would degrade the quality of captured image. In this paper, an effective coded exposure photography framework is proposed to help obtain better motion deblurring results. An integrated optimal fluttering pattern generation criterion with several factors is designed to guarantee
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Long-term Monitoring of zigzag-shaped concrete panel in retaining structure using laser scanning and analysis of influencing factors Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-06 Hyungjoon Seo
Retaining structures are required to evaluate their stability not only during construction but also during maintenance. In this paper, the retaining structure was constructed after excavating the slope for the tunnel construction. In order to evaluate the stability of a large-scale retaining structure, laser scanning was applied to monitor the behavior of the retaining structure. Since the retaining
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A three-dimensional measurement system calibration method based on red/blue orthogonal fringe projection Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-06 Jin Yu; Nan Gao; Zhaozong Meng; Zonghua Zhang
Structured light measurement system that consists of a camera and a projector has been widely used in three-dimensional (3-D) shape measurement. The premise of measurement is to calibrate the structured light system, and the calibration accuracy directly affects the accuracy of 3-D measurement system. The traditional calibration board-based methods suffer from either complex operations or uncompetitive
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Wavefront control through multi-layer scattering media using single-pixel detector for high-PSNR optical transmission Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-05 Yin Xiao; Lina Zhou; Wen Chen
We propose a new approach for optical analog-signal transmission through multi-layer scattering media using single-pixel detector to achieve high peak signal-to-noise ratio (PSNR), and analog signals can be experimentally received with high PSNR through multi-layer scattering media. The proposed approach, experimental observation and optical experimental results are presented that intensity of the
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A sensitive dynamic mutual encryption system based on a new 1D chaotic map Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-05 Mohamed Amine Midoun; Xingyuan Wang; Mohamed Zakariya Talhaoui
In this research paper, we propose a novel one-dimensional chaotic system based on the fraction of cosine over sine (1-DFCS). Evaluation of 1-DFCS indicates the existence of a complex chaotic behavior, an infinite chaotic range, and a high initial state sensitivity. We further propose a new sensitive dynamic mutual image encryption scheme (SDME) using 1-DFCS. SDME is designed with a dynamic diffusion
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Unitary learning for diffractive deep neural network Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-05 Yong-Liang Xiao; Sikun Li; Guohai Situ; Zhisheng You
Realization of deep learning with coherent diffraction has achieved remarkable development nowadays, which benefits on the fact that matrix multiplication can be optically executed in parallel with high band-with and low latency. Coherent optical field in the form of complex-valued entity can be manipulated into a task-oriented output. In this paper, a modulation mechanism is established by implementing
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Lens-based phase retrieval under spatially partially coherent illumination - Part II: Shape measurements Opt. Laser Eng. (IF 4.273) Pub Date : 2020-12-04 Mostafa Agour; Claas Falldorf; Fabian Thiemicke; Ralf B. Bergmann
We experimentally demonstrate the shape measurement of micro objects by means of phase retrieval under spatially partially coherent illumination. This approach offers an extended depth of focus, vibration insensitivity, short measurement time and precise shape measurements, enables the use of spatially extended light sources such as LEDs and thus significantly improves the eye safety of the method
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Inclination shift signal: thickness or index measurement in transparent media by transmission of generally astigmatic Gaussian beams Opt. Laser Eng. (IF 4.273) Pub Date : 2020-11-27 Andrés Daniel Aguilar; Jorge Román Torga
The focus error signal is a widespread optical technique that harnesses the shape of a simply astigmatic Gaussian beam to produce an output signal with a well-defined linear range used for many different applications. However, general astigmatic Gaussian beams have not been extensively used for measuring purposes even though they have been known for decades. These beams have interesting properties
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Single-pixel imaging for dynamic targets via a non-diffracting beam Opt. Laser Eng. (IF 4.273) Pub Date : 2020-11-26 Chunling Luo; Wenxiu Wan; Wenlin Gong
We develop a novel kind of single-pixel imaging (SPI) scheme to reconstruct high-quality images of the axially fast-moving target by utilizing the non-diffracting beam illumination. In this paper, a kind of cosine shaped source is elaborately designed and introduced for the first time in the SPI scheme to realize the reconstruction of the dynamic target. The imaging formula for the SPI system with
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On-line thin film thickness monitor by pulsed laser photoacoustics Opt. Laser Eng. (IF 4.273) Pub Date : 2020-11-26 Md Mahmudur Rahman; Hani E. Elsayed-Ali
On-line thickness monitor of thin film deposition by thermal evaporation is demonstrated using femtosecond pump-probe photoacoustics. A Ti:sapphire femtosecond laser (wavelength 800 nm, pulse width ~110 fs, pulse energy ~1.3 nJ) is split into a pump and a probe beams. The pump beam is used to instantaneously heat the illuminated area of an aluminum thin film during its deposition on a silicon substrate
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Non-central refractive camera calibration using co-planarity constraints for a photogrammetric system with an optical sphere cover Opt. Laser Eng. (IF 4.273) Pub Date : 2020-11-26 Wenjuan Yang; Xuhui Zhang; Hongwei Ma; Guangming Zhang; Gang Yang
Optical sphere covers are widely used in photogrammetric systems to protect camera systems from external conditions. The spherical refraction can cause severe non-linear distortion, resulting in imprecise and unreliable measurements. In particular the cameras with a relatively thick optical sphere cover (e.g. underground or underwater cameras). However, the conventional perspective camera model are
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Spatial filtering based terahertz imaging of low absorbing objects Opt. Laser Eng. (IF 4.273) Pub Date : 2020-11-24 Agnieszka Siemion; Linas Minkevičius; Liang Qi; Gintaras Valušis
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Seedingless measurement of density fluctuations and flow velocity using high-speed holographic interferometry in a swirl-stabilized flame Opt. Laser Eng. (IF 4.273) Pub Date : 2020-11-24 Johannes Gürtler; Felix Greiffenhagen; Jakob Woisetschläger; Robert Kuschmierz; Jürgen Czarske
Environmental protection is today’s major issue in the development of turbomachines. Especially, the reduction of pollutant and noise emission of aero engines and ground based gas turbines for power plants is a central task. Therefore, an improved understanding of the occurring complex flow phenomena in such turbomachines is necessary, which requires the investigation of influence and interaction of
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Total variation and block-matching 3D filtering-based image reconstruction for single-shot compressed ultrafast photography Opt. Laser Eng. (IF 4.273) Pub Date : 2020-11-22 Jiali Yao; Dalong Qi; Yunhua Yao; Fengyan Cao; Yilin He; Pengpeng Ding; Chengzhi Jin; Tianqing Jia; Jinyang Liang; Lianzhong Deng; Zhenrong Sun; Shian Zhang
Compressed ultrafast photography (CUP), as the fastest receive-only ultrafast imaging technology by combining steak imaging and compressed sensing (CS), has shown to be a powerful tool to measure ultrafast dynamic scenes. Through a reconstruction algorithm based on CS, CUP can capture the three-dimensional image information of non-repetitive transient events with a single exposure. However, it still
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