大气湍流对空间相干光通信的相干探测性能影响  

Influence of atmospheric turbulence on coherent detection performance of space coherent optical communication

作　　者：刘宇韬 徐苗 付兴虎[1] 付广伟[1] Liu Yu-Tao;Xu Miao;Fu Xing-Hu;Fu Guang-Wei(Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province,School of Information Science and Engineering,Yanshan University,Qinhuangdao 066004,China;Key Laboratory of Ocean Observation Technology,MNR,Tianjin 300112,China)

机构地区：[1]燕山大学信息科学与工程学院,河北省特种光纤与光纤传感重点实验室,秦皇岛066004 [2]自然资源部海洋观测技术重点实验室,天津300112

出　　处：《物理学报》2024年第10期203-211,共9页Acta Physica Sinica

基　　金：国家重点研究发展计划(批准号:2019YFC1407904);河北省自然科学基金(批准号:F2022203011);河北省高等学校科学技术研究项目(批准号:QN2022112);自然资源部海洋观测技术重点实验室开放基金(批准号:2021klootA07)资助的课题。

摘　　要：空间相干光通信被认为是突破现有高速空间通信瓶颈的重要手段,但其应用受到大气湍流的极大限制.为此,本文首先基于Huygens-Fresnel原理和低频补偿功率谱反演法,研究了高斯光束经大气湍流传输后振幅和相位的随机分布特性;然后,利用相干混频效率及通信误码率模型,获得大气湍流对空间相干光通信系统性能的影响规律;最后,搭建激光外差探测实验系统,定量研究了大气湍流对空间相干光通信相干探测性能的影响.结果表明:弱湍流条件下,空间相干光通信性能几乎不受大气湍流的影响;中等强度湍流影响下,相干混频效率会随着湍流强度的增大而迅速下降,但通过提高单比特光子数可以有效抑制湍流对通信性能的负面影响;强湍流会显著破坏光束相干性,使得相干混频效率趋近于零,即使提高单比特光子数也无法有效改善通信性能.大气湍流是空间相干光通信发展的重要限制因素,该研究可为空间相干光通信系统性能评估提供有益参考.Space coherent optical communication technology is considered to be an important way to overcome the bottleneck in current high-speed space communication.However,atmospheric turbulence seriously limits its realization.Based on the Huygens-Fresnel principle and the low-frequency compensation power spectrum inversion method,this work first investigates the random distribution characteristics of the amplitude and phase of a Gaussian beam after it has been transmitted through atmospheric turbulence.Then,using the coherent mixing efficiency and communication bit error rate model,the influence of atmospheric turbulence on the performance of spatial coherent optical communication systems is obtained.Finally,a laser heterodyne detection experimental system is built to quantitatively study the influence of atmospheric turbulence on the coherent detection performance of spatial coherent optical communication.The conclusions drawn from this study are as follows.1)The spatial phase distortion caused by the weak turbulence channel is relatively small and will hardly affect the light intensity distribution characteristics of the Gaussian beam.In the case of weak turbulence,the influence of weak turbulence on the performance of coherent optical communication system is almost negligible.The communication bit error rate will decrease rapidly with the increase of the number of single bit data photons.The communication signal-to-noise ratio can be better than 10^(-5) when the number of single-bit photons is greater than 10.2)Moderate turbulence will change the intensity distribution characteristics of the Gaussian beam,but will not cause a serious shift in the center of the spot.Under moderate turbulence conditions,the coherent mixing efficiency decreases rapidly as the turbulence intensity continues to increase,but the communication bit error rate still decreases rapidly with the increase of the number of single bit data photons.At this time,increasing the number of single-bit photons can suppress the negative influence of moderat

关 键 词：空间相干光通信 大气湍流 混频效率 误码率 

分 类 号：TN929.1[电子电信—通信与信息系统]