以双反射镜系统为基础,在其前后均增加一组折射光学元件来校正和平衡系统像差,设计了一款仅由2片反射镜和4片透镜组成的大相对孔径、长焦距且总长较短的折反射式望远物镜。该物镜系统的工作波段为400~700 nm,焦距为900 mm,入瞳直径为500 mm,遮拦比为0.43,系统总长为495 mm,全视场角范围内的调制传递函数值在截止频率为107.5 lp/mm处均大于0.5。最后对系统进行了公差分析。结果表明,设计的望远物镜系统具有结构简单、成像分辨率高且公差大等特点。

To correct and balance aberrations found in current systems, we designed a catadioptric telescope objective with a large relative aperture, long focal length, and short total length by adding a set of refraction optical elements before and after a double-mirror system. The working band of the objective system is 400-700 nm, focal length is 900 mm, diameter of the entrance pupil is 500 mm, obstruction ratio is 0.43, total length of the system is 495 mm, and value of modulation transfer function in the full field-of-view range is more than 0.5 at a cut-off frequency of 107.5 lp/mm. Tolerance analysis of the system was conducted. The results show that the telescope objective system designed in this study has the characteristics of a simple structure, high imaging resolution, and large tolerance.