Solving the twin image problem in in-line holography by using multiple defocused intensity images reconstructed from a single hologram

Abstract

Phase recovery from a hologram measurement is at the heart of coherent imaging techniques and online holography. In-line holography suffers from a blurred background problem that results from double images formed during hologram reconstruction. This so-called double image problem, inherent to the in-line geometry of the holographic experimental setup, limits the quality of the information (shape or refractive index of the object) obtained by reconstruction algorithms using a single hologram. We propose here a numerical reconstruction method combining the angular spectrum method (ASM) and the transport of intensity equation method using Gaussian process regression (GP-TIE) to solve this problem. In our approach, a single in-line hologram is used to recover the phase image free of any perturbation due to the presence of the double image.