Hybrid phase retrieval method for annular pupil

摘要

Phase retrieval method can determine pupil phase directly from image formed by the optical system with no extra hardware. This method has attracted more and more attentions for its unique advantage, and has been successfully applied in many domains such as large telescope alignment, X-ray imaging and so on. In this paper, we propose a hybrid phase retrieval method for annular pupil, which is composed of two steps. In the first step, the estimated spot images is computed with analytic expression, while fast Fourier transform is used in the second step. This method can achieve high retrieval speed without sacrificing the retrieval accuracy. Numerical simulation is performed to validate this phase retrieval method.