Fast-iterative blind phase-shifting digital holographic microscopy using two images

Digital holographic microscopy (DHM) has consolidated as a tool for diagnosis and measuring in life sciences, thanks to its capability to perform quantitative phase imaging. The reduction of the acquisition and computation time has driven the development of diverse reconstruction methodologies using a single-shot and two-frame approach. Methods based on the Fourier transform, the Hilbert transform, and the phase derivative are counted among the most utilized. The sensitivity of those methods is highly dependent on the compensation of the phase step, which requires the accurate knowledge of the phase shift between the two recorded holograms. Here, an alternative fast-iterative method based on the demodulation of the different components of the recorded interferograms is presented. The novelties of the proposed two-frame approach are: minimum number of images, since it requires 2 recorded holograms; a minimum phase error of the order of 0.005% independently of the phase step ranging from 0 to 180 deg.; a maximum correlation coefficient equal to 1 between the phase and the retrieved phase image; and, finally, a reduced processing time compared with the previous three-frame approach. Experimental results demonstrate the goodness and feasibility of the proposed technique. (C) 2020 Optical Society of America