环形光束大气传输数值模拟与分析

为了研究大气湍流对环形光束激光工程应用的影响，采用多相位屏数值模拟的方法对环形光束在大气湍流中的传输进行了仿真模拟。通过改变大气湍流强度、传输距离等参数，定量计算了不同传输条件下质心漂移均方根、远场目标的焦平面平均功率密度，给出环形光束传输路径上特征距离解析式并分析了大气湍流对环形光束远场平均光强分布的影响。结果表明，环形光束在大气湍流中传输时光斑质心漂移随湍流效应（湍流强度或传播距离）增强而增大，远场光束质量随遮拦比增大而降低。遮拦比小于0.5时，大气湍流对光束质量的影响较为明显。环形光束大气传输数值模拟方法，可为高能激光武器等激光工程应用的理论分析和效能评估提供依据。

Numerical simulation and analysis of annular beams propagation through atmospheric turbulence

In order to study the effect of the atmospheric turbulence on the annular laser beams,propagation of annular beams through atmospheric turbulence is simulated using multiple phase screen method.The wandering root mean square (RMS) of beam centroid and mean power density on the far-field target are computed quantitatively for different atmospheric turbulence strengths and propagation distances.With expressions for characteristic distance in the propagation path of annular beam described,influence of atmospheric turbulence on average intensity in far-field is also analyzed.Numerical simulation results show that the beam wander centroid displacement of annular beams increased as turbulent effects increased,and the far-field beam quality was degraded with the increase of obstruction ratio.The atmospheric turbulence can largely reduce the far-field beam quality when obstruction ratio was smaller than 0.5.This method of numerical simulation could be used for analyzing and evaluating the propagation effects in the field of laser engineering such as high energy laser.