设计了菲索式合成孔径望远镜光学系统, 用3个小口径子孔径合成大口径以获得等效大口径的分辨率。首先, 兼顾空间频率u-v覆盖和结构简单化, 选择子孔径排列方式为Golay-3阵列, 填充因子F=044。然后, 依据光学系统结构特性, 将光学系统分成子孔径、光束控制器和光束组合器, 分别进行光学设计。无焦式子孔径采用后接双胶合消色差透镜的卡塞格林结构, 孔径为300 mm, 视场为02°, 角放大率为10。光束组合器为五片式结构, 采用高折射率玻璃和特殊部分色散玻璃, 焦距为600 mm, F/#=6, 视场为2°。分析总系统点扩散函数和调制传递函数显示: 总系统等效口径为子孔径口径的189倍, 总系统角分辨率为024″。

An optical system for Fizeau-type synthetic aperture telescopes is designed by using three subapertures with small diameters to obtain the high resolution of an equivalent large aperture. First, considering both u-v covering of sparse frequency and structure simpleness, the Golay-3 array is choosen to be the subaperture arrangement and the filling factor F is 044. Then, according to the character of optical system configuration, the optical system is divided into the subapertures, ray controller and the ray combiner to be designed, respectively. The configuration of afocal subaperture is Cassegrain type with achromatic double lenses rearward, and its pupil diameter, Field of View(FOV) and angle magnification are 300 mm, 02° and 10, respectively. Moreover, the ray combiner is composed of 5 pieces of glass including high refractive index glass and special partial dispersion glass, and its focal length is 600 mm, F-number and FOV are 6 and 2. The Point Spread Function(PSF) and Modulation Transfer Function(MTF) of the subaperture are analysed, and the results show that the equivalent diameter of total system is 189 times that of the subaperture, and the angular resolution of total system is 024″.