子孔径拼接检测非球面时调整误差的补偿

针对在子孔径拼接测量非球面的过程中干涉仪与待测非球面相对位置存在的对准误差,提出了一种基于模式搜索迭代算法的调整误差补偿方法。该方法可以很好地从测量的子孔径相位数据中消除由拼接测量位置没有对准带来的调整误差,实现多个子孔径的精确拼接。对该方法的基本原理和实现步骤进行了分析和研究,建立了子孔径拼接测量的调整误差补偿模型。对口径为230 mm×141 mm的离轴碳化硅非球面反射镜进行了调整误差补偿和相位数据拼接,得到了精确的全口径面形分布。作为验证,对待测非球面进行了零位补偿检测,结果显示两种测试方法的面形PV值和RMS值的相对偏差仅为0.57%和2.74%。

Compensation of misalignment error on testing aspheric surface by subaperture stitching interferometry

For the purpose to decrease the misalignment error from a testing aspheric surface by Subaperture Stitching Interferometry（SSI）,a translated error compensation method is proposed to subtract the misalignment error from each phase detum and to stitch multi-subapertures precisely.The basic principle and process of the method are researched,and a compensation mode is established based on the mode search algorithm.The experiment is carried on for an off-axis SiC aspheric mirror with a clear aperture of 230 mm×141 mm,the phase data of the whole aperture are stitched precisely and the figure error is compensated by eliminating the misalignment error.For the comparison and validation,the asphere mirror is also tested by null compensation method,and the relative errors of PV and RMS are 0.57% and 2.74%,respectively.