光学天线光中比对外差效率的影响

OBSTRUCTION RATIO OF OPTICAL ANTENNA AND ITS EFFECT ON HETERODYNE EFFICIENCY OF LASER COHERENT DETECTION

本文采用光障比的概念,计算和分析了使用卡塞格仑中天线系统时,激光相干检测的外差效率。结果表明,均匀本振场时,在探测器半径R_o近似等于0.75倍信号场爱里斑半径R_A时,外差效率达到最大。使用天线比不使用天线对信号光场的到达角要求更严,其值差一个数量级。

Adopting the concept of obstruction ratio of the optical antenna, the heterodyne efficoncy of laser coherent detection of Casscgrianian telescope antenna are calculated and analysed. It is shown that the heterodyne efficiency could get the maxium value when the radius R_o of the optical detector is nearly eaqual to 0.75 R_A; and the arrival angle of the optical signal should be more accurate, when an antenna is used. The defference of the angle of arrival of the optical signal under the two circumstances (with or without an antenna )is one order of magnitude.