在利用剪切干涉测量共轴折返式光学系统波像差时,会得到含中心遮拦的环形剪切干涉图。但是,目前的剪切干涉波前重建方法大多适用于圆形或矩形区域。提出了一种适用于含中心遮拦环形剪切干涉图的波前重建方法。该方法是一种基于Zernike环多项式的模式法。仿真和分析了不同剪切比、单项像差、噪声对重建精度的影响,结果表明:该算法具有较高的重建精度,剪切比小于6%时,相对重建误差小于10%;对像散的重建精度较高,对球差和慧差的重建精度相对较低;具有较好的抗噪性。该方法已应用于实验室开发的交叉光栅横向剪切干涉仪的干涉图像波前重建中。
In the measurement of the wavefront aberration of on-axis reflective optical systems using shearing interference technology,there will be obscurations in the interferogram.However,the present wavefront reconstruction methods in shearing interference are mainly appropriate for circular or rectangular region.A wavefront reconstruction method is proposed which can apply to shearing interfergrams with central obscurations.The proposed method is a modal method based on Zernike annular polynomials.Effects of different shear ratio,different aberration and different noise on reconstruction accuracy are evaluated.The results show that this method has higher accuracy,the relative reconstruction error is below 10% with the shear ratio less than 6%,the reconstruction accuracy of astigmatism is higher than that of spherical aberration and coma,and has good noise immunity.This method is already used in the interferogram processing of cross grating lateral shearing interferomer developed in the laboratory.