卫星光通信系统的光学天线由物镜和目镜构成,两者在光轴方向的间距对系统的发射和接收性能有重要影响。轴间距通常由干涉仪确定,但干涉仪与光学天线的工作波长不同时会引起镜头组焦距变化,导致物镜和目镜的轴间距存在偏差。为了能利用单波长干涉仪精确调试物镜和目镜的轴间距,本文根据光学天线在干涉测量装置中的程函方程,研究了因波长差异引起的物镜和目镜的轴间距变化量与干涉条纹变化量的相应关系,并据此提出一种能精确调试光学天线物目镜轴间距的方法。提出了几种检验该方法有效性的验证方案,包括实验验证和计算机仿真验证两大类。基于计算机仿真的验证结果表明,卡塞格伦反射式光学天线和透射式光学天线轴间距模拟调试误差分别＜15%和＜3%,仿真误差满足使用要求。

The optical telescope of satellite optical communication terminal is composed of an objective and an eyepiece,and the axial center distance of the two lenses has an important influence on emitting and receiving performance of the system. The digital single-wavelength interferometer is an effective device to measure and adjust the axial center distance,however,it is usually difficult to be determined precisely when there is a wavelength difference between the interferometer and the optical telescope,because the focal length difference of the objective and the eyepiece varies with the wavelength. In this paper,the relation between the variations of center distance and the corresponding interference fringe counts was deduced on the basis of eikonal equation,then an efficient alignment method was given according to the relation. Several proof schemes including experiments and numerical simulation were suggested,and the second scheme was chosen to verify the alignment method presented in this paper. Numerical results show that the alignment error of center distance in a Cassegrain reflective optical telescope is less than 15%,and that in a refractive optical telescope is only about 3%. These results show that the proposed method can meet the alignment requirement of the satellite optical communication terminal.