海上大气激光传输特性仿真研究

大气光学效应是影响激光器作用效能的重要因素之一。基于多层相位屏法,针对海上大气环境下激光水平传输做了大量数值仿真,通过在湍流相位屏上叠加热晕以及衰减引起的相位变化,综合考虑三者对激光传输特性的影响；分析了不同激光初始功率、不同折射率结构常数、不同能见度以及有无热晕情况下接收面处激光光斑半径,质心漂移均方根和环围功率比的变化规律。仿真结果表明:激光初始功率越强,热晕效应越明显,光斑畸变越严重,光束质量变差；折射率结构常数越大,湍流效应越强,光斑扩展与光束漂移现象越明显,平均功率密度下降,环围功率比增加；能见度越小,激光能量衰减越严重,环围功率比越大；热晕效应会加大光斑扩展程度,增加光束漂移量和环围功率比。研究结果可为海上大气环境对激光器作用效能评估提供一定的理论依据。

Research on simulation of marine atmospheric laser transmission characteristics

Atmospheric optical effect is one of the important factors that affect the performance of lasers.Based on the multilayer phase screen method,a large number of numerical simulations are carried out for laser horizontal transmission in the marine atmospheric environment.By superimposing the phase change caused by the attenuation and the thermal blooming on the turbulence phase screen,the influence of the three factors on the laser transmission characteristics is considered comprehensively.The changing rule of the laser radius,centroid shift root mean square and energy circle rate under situation of different laser initial power,different refractive index structure constants,different visibility and presence or absence of thermal bloomingwere analyzed.The simulation results show that the stronger the laser initial power,the more obvious the thermal blooming effect,the more serious the spot distortion and the worse the beam quality;the larger the refractive index structure constant is,the stronger the turbulence effect is,the more obvious the spread of the spot and beam drift,the decrease of average power density and the increase of the energy circle rate;the smaller the visibility,the more serious the laser energyattenuation,the greater the energy circle rate;the thermal blooming effect will increase the spread of the spots,increase the beam drift and the energy circle rate.The research results can provide a theoretical basis for the evaluation of the effectiveness of the laser at marine atmosphere.