Hybrid method for accurate phase retrieval based on higher order transport of intensity equation and multiplane iteration

Abstract

Because phase contains specific information of the sample, especially transparent specimens such as biological cells and tissues, it is of utmost significance to accurately extract the phase. Although the phase can be directly solved from multiplane intensities through the prevalent transport of intensity equation (TIE) method, too many approximations in the solving process ultimately reduce its recovery accuracy. In addition, an iterative idea as a classic but potential tool allows quantitatively reconstructing phase while it is prone to trap in local stagnation due to nonconvexity. In order to restore the phase quantitatively and precisely, we propose a hybrid method combining the initial phase value via higher order TIE for system error reduction, and a final recovery solution using multiplane iteration for phase accuracy enhancement. Simulation and experimental results show that the proposed method not only has good noise suppression ability but also high phase recovery accuracy, and thus can be used in fields such as biological observation and medical diagnosis in the future.