基于相位恢复技术的大型光学镜面面形在位检测技术

In-situ Surface Measurement for Large Aperture Optical Mirror Based on Phase Retrieval Technology

根据目前大镜加工在位检测的需求和面临的困难,把基于衍射图像检测的相位恢复技术应用到大镜面形的在位检测,建立大镜加工在位检测系统。对影响测量系统精度的主要因素以及系统的抗振动性能进行了分析和仿真,结果表明该测量系统具有较好的抗振动能力,精度接近标准球面波光源的精度。基于GS迭代算法开发了测量软件,对φ500mm球面镜进行在位测量。把相位恢复测量结果与高精度的ZYGO干涉仪测量结果进行比较分析,结果表明在面形误差分布及误差的峰谷值(PV)和方均根值(RMS)上,两者具有较高程度的一致性,这说明相位恢复测量方法的可行性和准确性。由该方法构成的在位测量系统具有光路简单、精度较高、抗振动能力强和操作简单等特点,完全满足大镜的在位测量需求。

According to the present demand for in-situ surface measurement of large aperture optical mirrors and the difficulties faced, a new method based on phase retrieval technology is proposed and an in-situ measurement system is established. Main factors that influence the accuracy of measurement system and the anti-vibration ability of system are analyzed and simulated. The results show that the measurement system has good anti-vibration ability, and the accuracy is close to that of standard spherical wave light source. The measurement soRware is developed on the basis of GS iterative algorithm and in-situ measurement of a spherical mirror of Ф500mm is carried out. The measurement results show good agreement with those of high-precision ZYGO interferometer in error distribution, PV value and RMS value, which confirms the feasibility and accuracy of the measurement method based on phase retrieval. This in-situ measurement system features simple optical path, high accuracy, good anti-vibration ability and simple operation, thus fully satisfying the demand for in-situ measurement of large aperture optical mirrors.