针对空间光学系统长焦距、大视场、小型化、轻量化、大相对孔径、高成像质量的特点和发展趋势, 通过对非球面反射式光学系统设计模型及其理论参数的研究分析, 在共轴三反射式光学系统的基础上, 提出了一种离轴三反射式红外光学系统的设计方法。利用 ZEMAX求解并优化, 设计一个焦距 f＝1000 mm, 视场角为 4°, D/f＝1/4的反射式离轴光学系统。使该系统在 50 lp/mm空间频率处传函达到 0.3以上, 接近衍射极限, 全视场弥散斑控制在 10 μm以内, 满足空间照相机的需要。该系统克服了共轴三反存在中心遮挡的问题, 提高了系统的像质。

The developing trend and characteristics of the space optical system are long focal length, large view field, light weight, small dimension, large relative aperture and high image quality. A method of designing off-axial three-mirror anastigmat (TMA) infrared optical system is presented, through analyzing the design model and parameters of aspheric reflective optical system, based on coaxial three-reflective optical system. The structural parameters of the system can be solved and optimized by ZEMAX. Then the off-axial three-mirror system with focal length of 1000 mm, field of view of 4° and relative aperture of 1/4 is designed. After optimization, the modulation transform function (MTF) of field of view is 0.3 at 50 lp/mm, and the full field diffusion plaque is controlled into 10 μm. This system overcomes the central shielding problem which exists in coaxial TMA system. So the image quality of the system is greatly improved.