湍流大气对光束相干合成效果的影响  

Influence of turbulent atmosphere on the effect of coherent beam combining

作　　者：宋纪坤 李远洋[1] 车东博 郭劲[1] 王挺峰[1] 李志来[3] SONG Ji-kun;LI Yuan-yang;CHE Dong-bo;GUO Jin;WANG Ting-feng;LI Zhi-lai(State Key Laboratory of Laser Interaction with Matter,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China;Space Optical Department Ⅱ,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]中国科学院,长春光学精密机械与物理研究所激光与物质相互作用国家重点实验室,吉林长春130033 [2]中国科学院大学,北京100049 [3]中国科学院,长春光学精密机械与物理研究所空间光学研究二部,吉林长春130033

出　　处：《中国光学》2020年第4期884-898,共15页Chinese Optics

基　　金：国家重点研发计划资助项目(No.2016YFB0500100);国家自然科学基金资助项目(No.61805234);激光与物质相互作用国家重点实验室基金项目(No.SKLLIM1704);中国科学院前沿科学重点研究项目(No.QYZDB-SSW-SLH014);民用航天预研项目(No.D040101)。

摘　　要：光纤激光相干合成是获得高功率高光束质量输出较为有效的途径,而湍流大气是制约其应用与发展的关键因素之一。本文重点研究了大气格林伍德频率对基于随机并行梯度下降算法(SPGD)相干合成系统校正效果的影响。首先,在静态大气条件下,分析了不同湍流强度对相干合成系统校正效果的影响;然后,利用数值计算生成一组旋转的符合Kolmogorov统计规律的相位屏模拟湍流大气,对在不同大气格林伍德频率下相干合成系统的校正效果进行研究;最后,搭建两路光纤激光相干合成实验平台,进行实验验证。仿真和实验结果表明,在系统的控制算法迭代频率(350 Hz)一定时,随着大气格林伍德频率的增加,湍流大气对光束的相位和光强的扰动加剧,使得相干合成系统的合成效果变得越来越差。Coherent beam combining is a promising technology for achieving a high-power laser beam with good beam quality.However,turbulent atmosphere is one of the key factors that restrict its application and development.This paper focuses on the influence of atmospheric Greenwood frequency on the correction effect of the coherent combination system based on Stochastic Parallel Gradient Descent(SPGD)algorithm.At first,the influence of different turbulence intensities on the correction effect of coherent combination systems is analyzed by numerical simulation under static atmospheric conditions.Then,a set of rotating phase screens that meet Kolmogorov’s statistical law are generated by numerical calculation to simulate the turbulent atmosphere and study the correction effect of coherent combination system at different atmospheric Greenwood frequencies.Finally,an experimental platform is established to demonstrate the coherent combination effect of two laser beams.The simulated and experimental results show that when the system's control algorithm iteration frequency(350 Hz)is constant,the disturbance of turbulent atmosphere to the phase and light intensity of laser beams will increase with atmospheric Greenwood frequency,making the effect of coherent combination worse.

关 键 词：相干合成 SPGD算法 湍流大气 相位屏 

分 类 号：TN249[电子电信—物理电子学]