摘要
大气湍流效应是制约各种激光工程应用的重要因素之一。采用多层相位屏的模拟方法,针对地空激光大气的长距离斜程传输进行了大量数值模拟,通过变化天顶角、光束初始半径和激光波长等传输条件,定量分析了光束的有效半径、相对真空扩展倍数、光斑质心漂移均方根和63.2%环围能量的平均功率密度等统计参量在不同传输条件下受湍流的影响程度和变化规律。结果表明:天顶角越大,湍流效应越强,光束受到湍流的影响越大;波长越短,光束受到湍流的影响越强;光斑的漂移随光束初始半径的增大而减小,且与波长无关;在湍流效应和衍射效应的综合作用下,光束有效半径和63.2%环围能量的功率密度随波长和光束初始半径均不是单调变化。这可为激光工程应用提供一定的理论分析和性能预测依据。
Turbulent effect is an important factor to limit the application of laser engineering. By using multi-phase screen method, laser propagation along ground-space slant path was simulated. The characteristics of effective beam radius, relative beam spreading, wandering RMS of beam centroid and mean power density of 63.2% total power were analyzed quantitatively by changing zenith angle, initial beam radius and beam wavelength under different propagation conditions. It was found that with the increasing of zenith angle and the decreasing of beam wavelength, laser beam was more affected by atmospheric turbulence. Beam wandering decreased as initial beam radius increased and didn＇t change when beam wavelength changed. Under the combined influences of turbulent effects and diffraction, neither effective beam radius nor the mean power density of 63.2% total power changed monotonously with the increase of initial beam radius or beam wavelength. It could be used for predicting and evaluating the propagation effects in the field of laser engineering.
出处
《红外与激光工程》
EI
CSCD
北大核心
2008年第5期787-792,共6页
Infrared and Laser Engineering
基金
中国科学院知识创新工程重要方向资助课题(CXJJ-249)
关键词
光传播
地空斜程传输
湍流效应
数值模拟
Light propagation
Ground-space slant path propagation
Turbulent effects
Numerical simulation
