设计一种特殊的应用于计算全息法(CGH)高精度检测离轴凸非球面系统的照明系统。该照明系统一方面用作参考系统，另一方面将检测光近似垂直投射到待检测镜面上，使得检测系统为近似共光路系统，降低照明系统的制造精度。分析了照明系统的几何光路模型，将复杂的两用途系统简化，得到照明系统工作距离、照明系统焦距以及参考面曲率半径三个特征参量之间的关系。设计时，通过控制这几个特征参量，得到满足检测要求的系统初始结构。设计结果表明，该方法可以满足系统使用要求。

A special illuminating system is proposed and designed in order to accurately test convex off-axis aspherical mirrors with computer-generated holograms (CGH). Illuminating system is used as reference system and used to project testing beam on under-testing aspherical mirrors vertically and also makes testing beam and reference beam near common-path. The geometrical system of this illuminating system is introduced and analysed. Then the relation of characters of work distance, focal length and the curvature radius of reference surface of illuminating system is obtained after simplify this multipurpose system to simple model system. The initial system can be realized by controlling these characteristic parameters as merit function during optical design process. Design results show that this method can satisfy requirement of system use.