逆向传输标定法校正自适应光学非共光路像差  

Correction of Non-Common Optical Path Aberration in Adaptive Optics by Reverse Transmission Calibration Algorithm

作　　者：杨尚君 梁静远 吴加丽 柯熙政[1,2] Yang Shangjun;Liang Jingyuan;Wu Jiali;Ke Xizheng(School of Automation and Information Engineering,Xi'an University of Technology,Xi'an 710048,Shaanxi,China;Shaanxi CivilMilitary Integration Key Laboratory of Intelligence Collaborative Networks,Xi'an 710048,Shaanxi,China)

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048 [2]陕西省智能协同网络军民共建重点实验室,陕西西安710048

出　　处：《光学学报》2023年第12期94-104,共11页Acta Optica Sinica

基　　金：陕西省科研计划项目(18JK0341);陕西省重点产业创新项目(2017ZDCXL-GY-06-01);西安市科技计划项目(2020KJRC0083)。

摘　　要：自适应光学系统可以抑制大气湍流所产生的波前畸变,波前探测支路和光纤耦合支路之间存在的非共光路像差会导致自适应光学系统闭环后其耦合功率未能有效提升。采用逆向传输标定法由耦合光纤端到波前传感器进行反向传输,将波前传感器采集相对应的波前信息折算到自适应光学系统并实现闭环控制。结果表明:采用逆向传输标定法,数值仿真的耦合效率由27.31%提升至68.14%;静态环境实验的耦合效率由9.04%提升至45.21%;湍流环境实验的耦合效率由19.72%提升至36.93%;复杂环境实验的耦合效率由3.87%提升至7.52%。该方案简单而切实可行,易于在工程上推广应用。Objective Optical wireless coherent communication employs optical hybrid to complete the mixing of signal light and local oscillator light,and balance detectors to complete photoelectric conversion.Optical fiber hybrid has been widely applied in optical wireless coherent communication systems due to its advantages such as high integration and compact structure.It is necessary to efficiently couple spatial light into the optical fiber.Adaptive optical technology can improve the coupling efficiency from spatial light into optical fiber by correcting the distorted wavefront,and it is applied to optical wireless coherent communication systems.The existence of noncommon optical path aberration between the wavefront sensing branch and the coupling branch leads to the distorted wavefront in the communication branch after the closed loop of the adaptive optical system.The stochastic parallel gradient descent algorithm to correct the noncommon optical path aberration is easy to fall into the local optimum,and the phase difference algorithm employed to correct the noncommon optical path aberration is only applicable to the field of imaging systems.We propose a reverse transmission calibration algorithm to measure the noncommon optical path aberration for the initial calibration of adaptive optical systems in optical wireless coherent communication.Methods The adaptive optical system in wireless optical coherent communication is shown in Fig.1.After the laser beam is transmitted through the atmospheric turbulence,the beam is fully reflected by the deformable mirror.The reflected beam is divided into two collimated beams with a power ratio of 1:1 by the beamsplitter.One transmitted beam is to act on the wavefront sensor to monitor the current distorted wavefront.The other reflected beam is directly coupled into a singlemode fiber after being converged by a coupling lens for optical hybrid,coherent detection,and communication.Reverse transmission is sending the same beam from the receiver to the transmitter.A laser beam ident

关 键 词：光纤光学与光通信 无线光相干通信 自适应光学 光纤耦合 非共光路像差 

分 类 号：TN929.12[电子电信—通信与信息系统]