Phase inversion method based on focal length fixed Fresnel zone plate

The invention provides a phase inversion method based on a focal length fixed Fresnel zone plate. Part of focal plane and de-focal plane information of wavefront can be collected at the same time at the same position in the far field, only one frame of image is needed, the method based on the Fresnel zone plate is simple in components and is portable, accurate phase inversion can be realized on the basis of the single-frame far-field image, and the calculating speed and the precision are high. 本发明提供了种基于混合焦距菲涅耳波带片的相位反演方法，在远场同位置可以同时采集到部分波前的焦面和离焦面信息，只需帧图像，且基于菲涅耳波带片，元件简单，轻便，可实现基于单帧远场图像的准确相位反演计算，计算速度快、精度高。