设计了一种具有高发射和接收效率特性的激光通信光学系统。传统的卡式结构激光通信光学天线由于次镜的遮拦大大降低了发射效率，因此在设计中采用了偏瞳的卡塞格林光学天线，且收发共用，有效地提高了通信终端的发射效率和接收性能。对光学天线的增益、成像质量和传输效率等系统性能进行了分析，给出了共轴和偏轴情况下的系统收发增益曲线。同时，通过光谱分光的方法实现了通信收发光束、信标收发光束的高效隔离，大大减小了系统的体积和重量，降低了激光通信光学系统的复杂性，具有重要的参考意义和应用价值。

The concept of reflective eccentric-pupil Cassegrain antenna is introduced. Because the traditional on-axis Cassegrain antenna used in laser communication has obscuration, the efficiency of transmitting and receiving power is decreased greatly. This new kind of reflective eccentric-pupil Cassegrain antenna is unobscured, so it improves the efficiency of transmitting power and receiving power effectively. Its properties such as gain, image quality, and transmission efficiency are analyzed. The power decline curve is obtained by detailed analyzing the antenna system in partial axis situation. Besides, it is transceiver, so the system volume and weight are reduced greatly. The complexity is reduced enormously at the same time.