Wavefront measurement by phase retrieval through single defocus intensity patterns

An algorithm for wavefront measurement using a phase retrieval method is proposed. Only one defocus intensity pattern of the imaging optical system is needed for phase retrieval. Based on the extended Nijboer–Zernike (ENZ) approach, this algorithm draws on general inverse matrix theory, and a predictor–corrector method is also used to correct the linearization errors for medium-to-large aberrations. This method does not need multi-defocus intensity in the focal region, and it can exclude vibration during multi-intensity pattern capturing, making the whole process simple and brief. Some simulated results are presented which show this algorithm has good convergence against noise. A confirmatory experiment is carried out, and its results verifying this method are also given. (paper)