中文摘要：

当前对空间望远镜光学系统的要求是：在宽光谱范围内，系统具有分辨率高、质量轻等特点，衍射望远镜可以满足上述要求。利用Schupmann提出的消色差理论可实现系统宽光谱覆盖，采用平面衍射透镜做物镜可使系统轻量化，降低了成本。设计了一个物镜口径为1000mm，f／#=100，用离轴三反射镜做目镜的衍射望远镜。设计结果表明：系统在0．65-0．75μm波段，0．02°×0．035°视场范围内，得到了消色差，接近衍射极限的成像质量。

英文摘要：

The current requirements on space telescope are wide spectral coverage, high resolution, light weight,and the diffractive telescope can satisfy these requirements. With the help of flat diffractive lens, lighter weight, lower cost system is obtained based on Schupmann＇s achromatic theory,and such a system that has wide spectral coverage is designed. A design example of diffractive telescope is presented and the aperture of objective lens is 1 000 mm, f/#=100, off-axis three mirrors are used as eyepiece. It is shown that the system is achromatic and approximately attains diffraction limit at 0.65-0.75 μm, over the view field of 0.02°×0.035°.