机载激光通信中气动光学的影响及补偿

Boundary layer effect and compensation in airborne laser communication

为了抑制机载激光通信中大气附面层引起的散斑现象,开展了气动光学效应及相应补偿方法的研究。从理论上分析了气动光学效应对光传输的影响;根据试验飞机型号和设备安装位置,对光学窗口形状、厚度等参数进行了优化设计,并对窗口变形和空气流场分布进行了仿真分析,完成了光学窗口改造。最后,根据试验中大气附面层引起的接收光斑离焦现象,进行了光学仿真,研制了3种焦距的补偿镜。在飞行距离为10~140km,飞行高度为1 500~4 500m条件下进行了飞行试验,对不同补偿镜的补偿效果进行了分析。结果显示,在接收光路中增加焦距为5.5×105 m的凸透镜后,接收光斑离焦现象得到了抑制,接收光功率闪烁方差减小了1/3,表明经过补偿后的光学窗口可有效抑制大气附面层对激光通信的的影响。

To reduce the speckle phenomenon caused by atmospheric boundary layer on an optical window in airborne laser communication,the aero-optics effect and corresponding suppression method for the atmospheric boundary layer were discussed.Based on the type of experimental airplane and the position of equipment installation,the parameters of shape,thickness of the optical window were designed optimally,and the deformation of optical window and air flow field distribution were analyzed in the simulation and the optical window was improved.Finally,a series of compensating glasses were developed to solve defocusing of the receiving spot caused by the atmospheric boundary layer.A flight experiment was performed at the flight distance of 10-140 km and the flight altitude of 1 500-4 500 m and the compensation results were analyzed.The results show when the compensating glass with fi-nal focal length of 5.5×105 m is added into the receiving optical path,the atmospheric boundary layer is actively restrained by compensated optical window,the shape of receiving spot is improved and the receiving power distribution variance is reduced by 1/3.These results mean that the window after compensation reduces the effect of atmospheric boundary layer on laser communication effectively.