Two-Dimensional Phase Unwrapping by Direct Elimination of Rotational Vector Fields from Phase Gradients Obtained by Heterodyne Techniques

Abstract

Noting the analogy between electro-magnetic fields and the vector fields of phase gradients obtained by heterodyne techniques, we propose a new algorithm for least-squares phase unwrapping. Instead of solving a Poisson equation for the unwrapped phase map or using Green's formulation, we directly remove singular points or residues from the measured phase map by superposing sign-reversed vortex fields which cancel out the rotational vector fields associated with the phase singular points.