数字莫尔移相干涉仪误差多点标定与修正研究

Research on multi-point error calibration and correction of digital moiré phase-shifting interferometer

干涉测量在现有的光学元件面形检测方法中具有测量精度高的优势,应用相对广泛。但干涉仪元件的加工和装调误差会降低面形检测精度。提出一种利用夏克哈特曼波前传感器对实际干涉仪系统进行多点标定的方法,利用波前标定数据在光学设计软件ZEMAX中实现对虚拟干涉仪系统的修正,结合数字莫尔移相算法,消除实际干涉仪加工和装调误差的影响。选取平面镜和可变形镜作为待测镜分别进行面形测量实验,结果表明,标定和修正后的数字莫尔移相干涉仪系统检测精度提高,与Zygo干涉仪的检测结果相比,面形趋势保持一致且峰谷值（PV）值误差相差在0.07λ（λ=532 nm）以内。

Interferometry has a high measurement accuracy and a wide range of applications in the existing surface inspection methods of optical components. Fabrication and alignment errors in the interferometer reduces the accuracy of surface inspection. A multi-point calibration method of an actual interferometer system using a Shaker-Hartmann wavefront sensor is proposed. The correction of the virtual interferometer system is implemented in the optical design software ZEMAX using wavefront calibration data. Combined with digital Moiré phase-shifting algorithm, the influence of the fabrication and alignment errors in the actual interferometer are eliminated. A planar mirror and a deformable mirror are selected as the test mirrors for surface shape measurement experiments. The results show that the measurement accuracy of the digital Moiré phase-shifting interferometer system after calibration and correction is improved. Compared with the measurement results of the Zygo interferometer, the surface shapes are consistent and the peak-to-valley（PV） error difference is within 0.07λ（λ=532 nm）.