相移干涉术中参考波准直误差的数值校正

Correction of wave-front retrieval errors caused by the collimation errors of reference wave in phase-shifting interferometry

针对相移干涉术中参考波由于准直误差可能为非倾斜或倾斜球面波的情形,本文提出了一种简单的数字处理方法,不需任何附加测量即可提取真实球面波的几何参数,进而校正由标准波前再现公式所恢复的物波波前误差。本文方法的有效性由模拟试验所证实,并说明了其适用范围。

In phase-shifting interferometry（PSI） the standard wave retrieval formulae are usually derived based on the condition of a plane reference beam normal to the recording plane.In practice,however,the reference wave may be a spherical wave or even have a slight inclination due to the imperfect collimation and coaxality of the optical system,which will introduce phase distortion for the reconstructed object wave-front.A simple digital processing algorithm without any additional measurement is proposed in this paper to determine the unknown parameters of the spherical reference wave and then correct the object wave errors induced by the standard wave retrieval formulae.The effectiveness of this method is verified by simulations,and its limitation is also discussed.