相位片湍流仿真装置中的激光漂移效应

Laser wander effect in turbulence simulation system with random phase plate

为了在内场中开展激光传输特性实验研究,设计了一种基于Kolmogorov谱的随机相位片的大气湍流物理仿真系统,并用该大气湍流模拟仿真系统对激光漂移效应进行了研究。采用光束质量分析仪对模拟传输的光斑图像进行采集和分析,通过比较实际漂移方差与理论漂移方差,验证了该湍流仿真系统模拟和评价光束在仿真传输中的性能。实验分析表明,基于湍流相位片物理仿真系统模拟的光束漂移方差与理论曲线基本一致。

The laser propagation process can be influenced by atmospheric turbulence. The turbulence could bring on the degradation of the laser beam correlation, induce beam wandering and spreading. However, the experimental data obtained from the outer field research about laser propagation in turbulence is always influenced inevitably by many factors. A turbulence simulating device in inner field for studying the process of laser propagation in atmospheric turbulence could avoid the disturbance of these factors for studying. A physical turbulence simulation system using random phase plates based on Kotmogorov spectrum was designed to complete a spot wander experiment of laser propagation. The formula of instantaneous wander variance and beam ex- pansion variance are given, which could be used to determine long-term beam drift variance. In the experiment, a beam quality analyzer was used to gather and analyze the centroid data and diameter data of spot images, by which the long-term beam wander variance under interference of turbulence simulation could be work out. The experiment shows that laser spot wander angle wtriance of different simulation coherence length corresponds with the theoretical curve. The result shows that the turbulence simulation system is appropriate for the research of laser wandering effect in inner field.