根据激光通信系统中捕跟和通信探测器的实际应用情况, 分别使用消光比和单像元信噪比两种方案评价卡塞格伦光学天线的收发隔离能力,提出了在卡塞格伦光学天线次镜打孔和增加光陷阱的方式抑制后向散射的方法.推导得出当卡塞格伦光学天线次镜开孔的孔径比为0.1~0.3时不影响发射效率, 测试结果表明: 改进后的卡塞格伦光学天线收发隔离度优于－40 dB, 并满足激光通信系统光学天线捕跟和通信的使用要求.

Two schemes such as single pixel signal to noise ratio and extinction ratio are used to evaluate transmit-receive isolation ability based on the practical application of the tracking and communication detector in laser communication system. A method to inhibit the back scattering light was presented which boring a hole in the secondary mirror and increasing light trap. It is derived that when aperture ratio of secondary mirror K is 0.1~0.3, it dose not affect the emission efficiency,the measured results show that the improved Cassegrain optical antenna Transmit-Receive isolation is lower than －40 dB while not affecting the emission efficiency of system, and meet the requirements of laser communication system acquiring, tracking and communication.