基于位相测量偏折术的高精度检测平面光学元件面形的方法

针对位相测量偏折术（phase measuring deflectometry，PMD）在光学元件面形的高精度检测中存在面形低阶误差控制困难等问题，介绍了位相测量偏折术检测平面光学元件面形的基本原理，对有关PMD技术的面形改进重建算法、相对检测和四步剪切的系统误差扣除方法的研究进展进行了阐述，分析了基于PMD技术实现对口径398.7 mm×422.8 mm平板玻璃的拼接检测以及平面元件中可能存在的寄生反射影响的消除方法。指出建立的6相机斜率拼接检测系统的检测精度RMS可达1 μm，利用多频条纹法和二值条纹法可有效地消除寄生反射的影响，为大口径光学平面元件的前、后表面面形高精度检测提供一种可行的方案。

Method of optical flat elements surface figure detection with high accuracy based on phase measurement deflectormetry

Aiming at the phase measurement deflectormetry(PMD), it is difficult to control the low-order error of surface figure in optical elements surface figure detection with high accuracy. The basic principle of the optical flat elements surface figure detection by PMD was introduced. The research progress of improved surface figure reconstruction algorithm and systematic error deduction method of relative detection and four-step shearing of PMD technology was described. Based on PMD technology, the splicing detection of flat glass with the size of 398.7 mm×422.8 mm and the elimination method of parasitic reflection influence existed in the flat elements were analyzed. The RMS of detection accuracy of established 6-camera slope splicing detection system could reach to 1 μm. Multi-frequency fringe method and binary fringe method could be effectively eliminated the influence of parasitic reflection, which provided a feasible scheme for the surface figure detection with high accuracy of front and rear surfaces of the large-caliber optical flat elements.