子孔径拼接法检验大口径光学镜面精度分析

介绍子孔径拼接检测大口径光学镜面的原理，即用小口径的平面干涉仪检验大口径平面的一部分，通过改变2者相对位置获得覆盖到整个被检验镜面的子孔径检测数据。提出利用最小二乘法对相邻2个子孔径重叠部分的检测数据进行计算来确定实际所有子孔径之间的位置关系，进而得到拼接而成的整体面形信息。并对子孔径拼接成的面型与实际面型的误差进行分析，建立了对子孔径拼接全口径波面恢复精度的评价指标。根据子孔径拼接原理完成了实验，并对多组子孔径数据拼接后的波面恢复精度进行了分析。实验证明，子孔径拼接检测大口径光学元件综合误差小，重复精度高。

Accuracy analysis of stitching interferometry for test of large-diameter mirror

The principle of stitching interferometry for testing the large plane optics is presented in this paper. The relative placements of both interferometer and the mirror under test can be adjusted, and interferometric test of subaperture can be done over the whole part of the mirror surface under test. The wave-front data in the overlapping areas of adjacent subapertures are analyzed by using the least-square algorithm. The relationship between the tested subapertures is clarified step by step. Finally subapertures are stitched together, and full aperture surface shape under test is synthesized. The error between the spliced surface by stitching interferometry and the actual surface is analyzed, and the accuracy of stitching interferomertry is evaluated. The experiment based on the theory of stitching interferometry was done. The results indicate that the stitching interferometry is an effective means to measure large-aperture optics accurately.