光学元件拼接测量中的定位误差校正  

Position error compensation for large-aperture mirror stitching measurement

作　　者：刘丁枭 李明[1,2] 盛伟繁 LIU Dingxiao;LI Ming;SHENG Weifan(Institution of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院高能物理研究所,北京100049 [2]中国科学院大学,北京100049

出　　处：《核技术》2019年第1期13-19,共7页Nuclear Techniques

基　　金：国家自然科学基金青年基金(No.11005123)资助~~

摘　　要：为了实现大口径反射光学元件表面面形的高精度测量,建立了拼接测量方法,用以得到光学元件表面的面形数据。但拼接测量存在较多误差,其中各局部面形之间的定位误差对拼接误差影响较大,需要通过校正来减少定位误差对拼接误差的影响。首先对被测镜进行局部面形划分,按着一定顺序完成所有局部面形的测量;然后,基于BFGS算法对各子口径面形之间的定位误差进行校正求解,进而得到整体面形数据;最后,使用ZYGO菲索干涉仪搭建了拼接测量设备,对反射镜中120 mm×20 mm的区域进行测量,将直接拼接方法与位移校正拼接方法获得的面形数据与全口径整体测量获得的面形数据进行了对比,位移校正拼接方法测量面形数据与全口径拼接测量面形数据残差小,结果表明该方法可以有效提高拼接测量精度。[Background]In order to realize the high precision measurement of large-aperture mirror,a stitching method is established.The position errors between adjacent surfaces affect the stitching results,so compensation algorithm is needed to solve this problem.[Purpose]This study aims to reduce the effect of position errors in stitching measurement by proposing a global optimization algorithm for position error compensation.[Methods]Firstly,the basic theory of stitching measurement technology is applied to dividing the whole test mirror into several parts,each part of the surface should meet the requirement of a single measurement.Then,based on BFGS algorithm,pixel motion and two-dimensional linear interpolation,a stitching method for compensating position error is established.Finally,a ZYGO Fissor interferometer is employed to construct stitching measurement equipment to measure the 120 mm×20 mm area in reflector by using stitching measurement method.[Results]Compared with full aperture measurement,the peak-valley(PV)and root mean square(RMS)of the height residual achieved by stitching measurement are 8.7 nm and 0.5 nm,respectively.[Conclusions]The experiment result showed that this optimization method can compensate the position error more effectively than the direct stitching method.

关 键 词：大口径光学元件 干涉 光学测量 拼接 

分 类 号：TL99[核科学技术—核技术及应用]