Phase-shifting Error Compensation for Phase-shifting Digital Holography Microscopy

Phase-shifting digital holography microscopy has attracted much interest, because it adopts the in-line configuration, thus it can make full use of the resolution of digital camera. However, phase-shifting error becomes major error source for the reconstruction of the interferograms. In this paper, a numerical method to quantitatively detect and compensate the phase-shifting error is proposed, for three-step phase-shifting digital holography microscopy. For common cases having small phase-shifting error, this method detects the phase-shifting errors through an analytical criterion; otherwise, it employs Newton-Raphson iterative method to improve the detection accuracy to a high level. In addition, this method works in some selected area of the interferograms, which is also used to fit the parameters of micro-objective, so it does not require the amplitude of object wave being constant in full field of interferograms. The feasibility of this method is demonstrated by both computer simulation and experiment.