Principle of a linear phase retrieval method and its application in adaptive optics system

The basic principle of the linear phase retrieval (LPR) method is introduced. It is found that in small phase condition, the odd and even parts of phase aberration can be obtained uniquely with a simple linear calculation method. The difference between a single measured image with aberration and the calibrated image with inherent aberration are used to retrieve aberration phases. In this paper, the principle of LPR and its application in close-loop AO system are introduced in vector-matrix format, which is a kind of linear calculation and is suitable for real-time calculation. Although the LPR method is limited for small aberrations only, it is suitable to use as a wavefront sensor in close-loop adaptive optical system. The performances of the LPR method are tested in a close-loop adaptive optics system with PZT deformable mirror. The experiment results show that the LPR method can be performed in real time and achieve good capabilities.