Analysis of spatial resolution and pinhole size for single-shot point-diffraction interferometer using in closed-loop adaptive optics

A closed-loop adaptive optics system using a single-shot point-diffraction interferometer (PDI) and a liquid crystal spatial light modulator is presented. Only one CCD camera is required to achieve simultaneous acquisition of four phase-stepped interference patterns, and then the aberrated wavefront is directly reconstructed with a simple algorithm. To reasonably choose or utilize the photosensitive area of a single camera using in this class of single-shot interferometers, the relationship of the spatial resolution and the reconstructed accuracy is analyzed. Additionally, to increase the intensity transmission to the utmost extent and thus improve the visibility of interference patterns especially in the beginning of closed-loop correction, the maximal pinhole size allowed in a closed-loop adaptive optics is studied. Numerical simulation and closed-loop correction experiments are performed.