Synchronous two-step phase-shifting interference

Currently, synchronous phase-shifting interferometry often requires specific optical components or introduces additional phase due to different optical elements in the paths of object and reference beams. To address this issue, we proposed a synchronous phase-shifting interferometer. This interferometer is adapted from a Mach-Zehnder interferometer and can simultaneously capture two phase-shifting holograms. Based on the existing algorithm of phase retrieval, we conducted the theoretical derivation, simulated and experimental work to confirm the feasibility of our system preliminarily.