检索结果-内蒙古大学图书馆

Automation, Control and Robotics Engineering (CACRE), International Conference on

作者： Tianyu Zhang Zhizheng Wu Xiang Wei Feng Li Jialiang Wu Kongbin Zhu Department of Precision Mechanical Engineering Shanghai University School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology

ISBN: (数字)9781728198880

ISBN: (纸本)9781728198897

Laser scanning confocal microscopy(LSCM) has become a common method for biological observation and medical science. Compared with traditional optical microscope, LSCM has the advantages of high contrast and three-dimensional(3 D) imaging. However, with the increase of image depth, the resolution and contrast will be reduced due to the complexity of biological tissue aberrations. Adaptive optics system is an effective method to eliminate aberration. In this paper, a wavefront sensorless adaptive optics system is used to correct aberrations generated by complex refractive index of biological tissue. In order to increase the convergence speed and reduce the influence of photobleaching, an improved stochastic parallel gradient descent algorithm with adaptive coefficient is used to control the AO system. The optical path is simulated in ZEMAX and the feasibility of the proposed algorithm is verified in MATLAB. All simulation results demonstrate that the optimal algorithm can correct the aberration effectively with the designed optical system.

关键词： Laser scanning confocal microscope adaptive optics aberration correction spgd algorithm adaptive coefficient

来源：评论

学校读者我要写书评

暂无评论

Develop the Fiber Coupling Efficiency Based on spgd Control algorithm 9

Develop the Fiber Coupling Efficiency Based on SPGD Control ...

引用

9th International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT) - Optical Test, Measurement Technology, and Equipment

作者： Wu, Shuiqin Ren, Wei Mao, Yao Liu, Qiong Duan, Qianwen Chinese Acad Sci Key Lab Opt Engn Chengdu 610209 Sichuan Peoples R China Chinese Acad Sci Inst Opt & Elect Chengdu 610209 Sichuan Peoples R China Univ Chinese Acad Sci Beijing 100039 Peoples R China

ISBN: (数字)9781510623217

ISBN: (纸本)9781510623217

In the satellite-to-ground laser communication, the beacon light is affected by atmospheric turbulence, atmospheric scattering and atmospheric absorption, so there is a coupling error. And the receiving end of ATP system is affected by random disturbance which lead to the initial coupling place change. The above reasons resulting in the fiber coupling energy decline. The efficiency of fiber coupling directly affects the success rate of decoding, so it is important to improve the efficiency of fiber coupling. This paper uses a tilt mirror which has cheaper cost and simple structure compared to wavefront corrector as the actuator for optical fiber coupling alignment and use the two-dimensional stochastic parallel gradient descent algorithm (spgd algorithm) widely used in the field of adaptive optics to correct the coupling errors caused by atmospheric turbulence and random disturbance at the receiving end. The spgd algorithm is affected by the initial coupling position, when the initial coupling position is unreasonable, the spgd algorithm cannot be used for effective coupling. Therefore, the CCD camera is used as a position sensor to obtain a reasonable initial coupling position and improve the fiber coupling efficiency of the system.

关键词： spgd algorithm Fiber Coupling Efficiency satellite-to-ground laser communications Tilt mirror

来源：评论

学校读者我要写书评

暂无评论

A new version of Stochastic-parallel-gradient-descent algorithm (spgd) for phase correction of a distorted orbital angular momentum (OAM) beam 4

A new version of Stochastic-parallel-gradient-descent algori...

引用

4th Seminar on Novel Optoelectronic Detection Technology and Application

作者： Yin, Xiao-li Lin, Jiao-Ling Chang, Huan Cui, Xiao-zhou Guo, Yi-Lin Liao, Huan-Yu Gao, Chun-Yu Wu, Guo-hua Liu, Guang-Yao Jiang, Jin-Kun Tian, Qing-Hua Beijing Univ Posts & Telecommun Sch Elect Engn Beijing 100876 Peoples R China Beijing Univ Posts & Telecommun Beijing Key Lab Space Ground Interconnect & Conve Beijing 100876 Peoples R China Beijing Univ Posts & Telecommun State Key Lab Informat Photon & Opt Commun Beijing 100876 Peoples R China

ISBN: (数字)9781510619487

ISBN: (纸本)9781510619487

Atmospheric turbulence limits the performance of orbital angular momentum-based free-space optical communication (FSO-OAM) system. In order to compensate phase distortion induced by atmospheric turbulence, wavefront sensorless adaptive optics (WSAO) has been proposed and studied in recent years. In this paper a new version of spgd called MZ-spgd, which combines the Z-spgd based on the deformable mirror influence function and the M-spgd based on the Zernike polynomials, is proposed. Numerical simulations show that the hybrid method decreases convergence times markedly but can achieve the same compensated effect compared to Z-spgd and M-spgd.

关键词： OAM adaptive optics WSAO spgd algorithm

来源：评论

学校读者我要写书评

暂无评论

Kspgd algorithm to restrain the influence of measurement noise in adaptive fiber coupling

引用

OPTICAL ENGINEERING 2024年第4期63卷 041202-041202页

作者： Peng, Jinjin Mao, Yao Qi, Bo Chinese Acad Sci Key Lab Engn Chengdu Peoples R China Chinese Acad Sci Inst Opt & Elect Chengdu Peoples R China Univ Chinese Acad Sci Beijing Peoples R China

The adaptive coupling of the laser beam from space to single-mode fiber plays an important role in free space optical communication. A typical adaptive algorithm is stochastic parallel gradient descent algorithm (spgd), which measures the performance index value to estimate the gradient value to maximize the coupling efficiency. It is conceivable that the presence of performance index measurement noise will have a great influence on the convergence performance of the algorithm. We propose an improved Kalman stochastic parallel gradient descent algorithm (Kspgd). Specifically, considering the influence of measurement noise on gradient estimation, we introduce the gradient prediction model in the iterative optimization process and then use the Kalman filter to estimate the gradient of the current iteration point. Kalman filter algorithm and optimization algorithm are integrated together. Simulation and experimental results show that the Kspgd algorithm can better restrain the influence of measurement noise on the convergence performance of the algorithm than the spgd algorithm. (c) 2023 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： free space optical communication fiber coupling spgd algorithm measurement noise Kalman filter

来源：评论

学校读者我要写书评

暂无评论

Theory of Admspgd algorithm in fiber laser coherent synthesis

引用

OPTICS COMMUNICATIONS 2021年 492卷 126953-126953页

作者： Che, Dongbo Li, Yuanyang Wu, Yunhan Song, Jikun Wang, Tingfeng Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys State Key Lab Laser Interact Matter Changchun 130033 Peoples R China Univ Chinese Acad Sci Ctr Mat Sci & Optoelect Engn Beijing 100049 Peoples R China

The stochastic parallel gradient descent (spgd) algorithm is one of the promising approaches for performing an efficient coherent beam combining (CBC) for power-scaling of the fiber lasers. However, this algorithm likewise suffers from certain shortcomings, including slow convergence speed and ease catching into local extremes. This paper proposes an Admspgd algorithm that modifies the conventional one with adaptive gain and momentum. Notably, the adaptive gain coefficient improves convergence speed by adjusting such gain coefficient in realtime, while the momentum factor suppresses high-frequency interference by adjusting update direction. The proposed algorithm is testified through relevant simulations and experiments, whose results depict that the proposed algorithm can significantly increase convergence speed, robustness and effective bandwidth in the fiber laser beam combining system.

关键词： spgd algorithm Gain coefficient Gradient estimation Laser coherent synthesis

来源：评论

学校读者我要写书评

暂无评论

Correcting dynamic residual aberrations of conformal optical systems using AO technology

引用

Chinese Physics B 2009年第7期18卷 2769-2773页

作者：李岩李林黄一帆杜保林 Department of Optoelectronic Engineering Beijing Institute of Technology

This paper analyses the dynamic residual aberrations of a conformal optical system and introduces adaptive optics （AO） correction technology to this system. The image sharpening AO system is chosen as the correction *** between MATLAB and Code V is established via ActiveX technique in computer *** spgd algorithm is operated at seven zoom positions to calculate the optimized surface shape of the deformable *** comparison of performance of the corrected system with the baseline system,AO technology is proved to be a good way of correcting the dynamic residual aberration in conformal optical design.

关键词： conformal optical design dynamic residual aberration spgd algorithm micro-electro-mechanical systems deformable mirror

来源：评论

学校读者我要写书评

暂无评论

Incoherent beam combining using fast steering mirrors

引用

JOURNAL OF MODERN OPTICS 2017年第3期64卷 251-258页

作者： Yang, Guoqing Liu, Lisheng Jiang, Zhenhua Wang, Tingfeng Guo, Jin Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys State Key Lab Laser Interact Matter Changchun Peoples R China Univ Chinese Acad Sci Beijing Peoples R China

Incoherent beam combining (ICBC) is a promising technique that can increase the total power of the lasers without decreasing the beam quality. Fast steering mirror (FSM) can be used in ICBC system to overlap the laser beams as well as suppress the jitter of the platform and the tip-tilt component of the turbulence. In this paper, a method using FSMs for incoherent beam combining is proposed and the relationship between the emergent light and the control voltages is derived, then the stochastic parallel gradient descent algorithm is adopted to calculate the optimal control voltages applied to the FSMs. A series of simulations combining two laser beams are carried on under static and dynamic turbulence. In order to verify the feasibility of this scheme, the dynamic turbulence is simulated under the hypothesis of Taylor's frozen turbulence. The results of simulations show that the turbulence would severely degrade the result of combining and the correction process would resist the influence and assure the evaluation function can reach the ideal situation at last. The model of the scheme used in this paper can be easily utilized for arbitrary amount of the lasers.

关键词： Laser beam combining dynamic turbulence spgd algorithm fast steering mirror

来源：评论

学校读者我要写书评

暂无评论

Incoherent beam combining based on imperialist competitive algorithm

引用

OPTIK 2018年 168卷 1-9页

作者： Song, Jikun Yang, Guoqing Li, Yuanyang Wang, Tingfeng Chinese Acad Sci State Key Lab Laser Interact Matter Changchun Inst Opt Fine Mech & Phys Changchun 130033 Jilin Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

Incoherent beam combining is an extremely efficient method to achieve high-energy laser output. In this paper, we present the numerical study on the incoherent beam combining using imperialist competitive algorithm (ICA). The feasibility is validated by the simulation of incoherent beam combining system using the ICA under the conditions of free space. The capability of ICA under the different condition of atmosphere turbulence is numerically studied by simulation. It is revealed that ICA is a feasible means for beam combining system even under the condition of strong turbulence. Further, the performance of ICA for incoherent beam combining is compared with a widely used stochastic parallel gradient descent (spgd) algorithm. The ICA have a small number of iterations and satisfactory correction effect compared with spgd algorithm. Therefore, the ICA is a promising method for beam combining system. (C) 2018 Elsevier GmbH. All rights reserved.

关键词： Incoherent beam combining Imperialist competitive algorithm spgd algorithm

来源：评论

学校读者我要写书评

暂无评论

Telescopes Alignment Using the Sharpness Function Method Based on Undersampled Images

IEEE PHOTONICS JOURNAL

引用

IEEE PHOTONICS JOURNAL 2019年第1期11卷 1-14页

作者： Li, Min Liu, Xin Zhang, Ang Xian, Hao Chinese Acad Sci Key Lab Adapt Opt Chengdu 610209 Sichuan Peoples R China Chinese Acad Sci Inst Opt & Elect Chengdu 610209 Sichuan Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

In astronomy, the images are sometimes undersampled. In the previous research works, image reconstructions have to be employed to recover the lost information from a set of undersampled images to achieve a high-resolution image using dithering or drizzle methods, which increase the complexity of alignment processes and make the real-time correction impossible. In this paper, the telescope is aligned by changing the positions of the secondary mirror using sharpness function method combined with the stochastic parallel gradient descent algorithm based on both well-sampled and undersampled images without image reconstructions. To improve the accuracy and robustness of the alignment, a new metric called relative root mean square error is proposed. Both numerical simulations and experiments are implemented, and the alignment precisions are measured by wavefront residual errors using Shack-Hartmann wavefront sensors. The results show that the correction processes can converge stably and quickly whether the images are well-sampled or undersampled. In experiments, the average wavefront error is 0.0595 lambda for undersampled images and 0.0548 lambda for well-sampled images after the telescope alignment, indicating that the misalignments are well compensated for both well-sampled and undersampled images.

关键词： Telescope alignment spgd algorithm relative RMS errors under-sampled images

来源：评论

学校读者我要写书评

暂无评论

Study on Factors Degrading the Accuracy of Real Beam Modal Decomposition

引用

CURRENT OPTICS AND PHOTONICS 2021年第2期5卷 93-100页

作者： Choi, Kyuhong Kim, Youngchan Yun, Youngsun Noh, Young-Chul Jun, Changsu Gwangju Inst Sci & Technol Adv Photon Res Inst Gwangju 61005 South Korea

Three factors that degrade the accuracy of modal decomposition are extensively studied using simulated and measured beams. These include a beam size mismatch, beam center mismatch, and signal-to-noise ratio of the images. The beam size and beam center are scanned using simulated noisy beams, and the result of the modal decomposition is compared with that of real beams. Based on the suggested procedure, error functions of approximately 1-4 x 10(-3) can be acquired for real beams. This study provides important information regarding the impact of the three factors on the practical modal decomposition and tolerances of a mismatch, helping estimate the achievable values of the error function in a real beam modal decomposition.

关键词： Beam analysis Fiber laser Modal decomposition spgd algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：