大口径凸非球面反射镜子孔径拼接检测

为了获得大口径凸非球面反射镜全口径的面形，提出了利用子孔径拼接检测大口径凸非球面的新方法。利用干涉仪标准球面波前依次干涉测定大口径镜面上各个区域的相位分布，通过子孔径拼接算法即可求解得到镜面全口径面形信息。对该方法的基本原理和实现步骤进行了分析和研究，建立了大口径拼接检测算法的数学模型，设计并研制了大口径反射镜拼接检验装置。结合实例对一口径为260 mm 的碳化硅凸非球面反射镜进行了9 个子孔径的拼接干涉测量，并将拼接检测结果与全口径面形测量结果进行对比，两种方法测量面形PV 值和RMS 值的偏差分别为0.043和0.021（=632.8 nm）。

Test on large convex aspherical mirror by subaperture stitching interferometry

In order to obtain the figure error of the whole large convex aspherical mirror, a new method for testing large convex asphere by subaperture stitching and interferometry so called SSI was proposed. A perfect sphere mirror was used as the reference surface, the phase distribution of each subaperture could be measured by the digital wavefront interferometer, and the full surface map could be calculated by stitching several subapertures. The basic principle and theory of SSI were studied, the stitching process and prototype for test of large aspheres were devised and developed, and the setup of SSI for measuring of large aspherical surface was designed and manufactured. A convex SiC asphere mirror with the aperture of 260 mm was tested by SSI with 9 subapertures. For the validation, the aspheric mirror was also measured by null compensation, the difference of PV and RMS error was 0.043 and 0.021, respectively ( is 632.8 nm). It provides an another accurate testing method for aspherical surface especially for large convex aspherical mirror.