大气湍流对接收光场时间相干特性的影响  

Influence of atmospheric turbulence on temporal coherence characteristics of received optical field

作　　者：艾则孜姑丽·阿不都克热木 陶志炜 刘世韦 李艳玲 饶瑞中[1,4] 任益充 Abdikirim Azizigul;Tao Zhi-Wei;Liu Shi-Wei;Li Yan-Ling;Rao Rui-Zhong;Ren Yi-Chong(Key Laboratory of Atmospheric Optics,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;Science Island Branch,Graduate School of University of Science and Technology of China,Hefei 230026,China;School of Environmental Science and Optoelectronic Technology,University of Science and Technology of China,Hefei 230026,China;Advanced Laser Technology Anhui Laboratory,Hefei 230037,China)

机构地区：[1]中国科学院合肥物质科学研究院,安徽光学精密机械研究所,中国科学院大气光学重点实验室,合肥230031 [2]中国科学技术大学研究生院科学岛分院,合肥230026 [3]中国科学技术大学环境科学与光电技术学院,合肥230026 [4]先进激光技术安徽省实验室,合肥230037

出　　处：《物理学报》2022年第23期245-252,共8页Acta Physica Sinica

基　　金：安徽省自然科学基金青年项目(批准号:1908085QA37);国家自然科学基金青年科学基金(批准号:11904369);脉冲功率激光技术国家重点实验室主任基金(批准号:2019ZR07)资助的课题.

摘　　要：激光在大气传输过程中其相干特性受湍流影响而下降,进一步影响相干探测过程的效率和性能.本文定义大气相干时间描述激光经大气传输后接收光场的起伏速度,大气相干时间与相干过程持续时间的相对大小决定了相干探测过程的性能.本文基于多层动态相位屏技术仿真激光大气传输过程,并系统研究大气参数、收发参数、波长等对大气相干时间的影响规律.研究指出大气相干时间与波长、接收口径、大气相干长度呈正相关,与风速呈反比;通过改进光学设计、光束整形、激光选频等方法能够有效减少湍流扰动的影响,提高接收光场的稳定性,进而改善湍流对相干探测过程的不良影响.大气相干时间是衡量湍流对相干探测影响的重要参数,本研究可为评估大气对相干探测过程的影响提供有力参考.In the process of laser propagation in atmosphere,its coherence characteristics are reduced by turbulence,which further affects the efficiency and performance of coherent detection process.In this paper,atmospheric coherence time is defined to describe the fluctuation speed of laser field after atmospheric transmission.The relative size of atmospheric coherence time and coherence process duration time determines the performance of coherent detection process.According to the infinitely long phase screen technology,we simulate laser atmospheric transmission,and systematically study the influences of atmospheric parameters,transceiver parameters and wavelength on atmospheric coherence time.It is found that the atmospheric coherence time is positively correlated with wavelength,receiving aperture and atmospheric coherence length,and inversely proportional to wind speed,which shows that the atmospheric coherence time can be effectively improved by improving the optical design and changing the laser band,thus effectively reducing the disturbance caused by turbulence and improving the stability of the received light field.The atmospheric coherence time defined in this paper is an important parameter to measure the influence of turbulence on coherent detection.This study can provide a powerful reference for evaluating the influence of atmosphere on coherent detection process.

关 键 词：相干探测 大气湍流 大气相干时间 多层动态相位屏 

分 类 号：O357.5[理学—流体力学] TN24[理学—力学]