Cassegrain光学天线系统的优化设计

摘要

由于空间光通信中采用的激光束的光场分布呈高斯分布，反射镜对光线的遮挡将严重影响天线的传输效率，从而导致通信质量的下降，针对Cassegrain光学天线，对光学天线的系统结构以及次镜遮拦对天线增益的影响进行了分析，并根据高斯光束经过光学系统的变换与传输特性，分析了采用Cassegrain天线时，遮拦比以及入射光束束腰对光束透过率的影响，提出了一种提高光学天线传输效率的新方案，改进后的天线系统，使得传输效率有了显著提高。%The obscuration caused by the Gaussian distribution of the laser beam in the space optical communication will affect the transmission efficiency of the antenna seriously,which leads to a drop in the quality of communication.The system structure of the optical antenna and the influence on the antenna gain is analyzed,which is caused by the obscuration of the secondary mirror in view of the Cassegrain. According to the transformation and transmission char-acteristics of Gaussian beams through the optical system,the effect of the obscuration and incident beam waist on the light transmittance is analyzed when Cassegrain antenna is used,and a new way is proposed to improve the transfer ef-ficiency of the optical antenna. The improved antenna system makes its transmission efficiency improve significantly.