Vortex Stagnation problem in iterative Fourier transform algorithms

Optical vortex stagnation problem in Iterative Fourier Transform Algorithm occurs due to the termination of the process of self annihilation of optical vortices. The role played by propagation and inverse propagation operators combined with the Fourier domain constraint in this vortex annihilation process in the initial stage of the iterative procedure is studied. The understanding of this process recommends the process of forced annihilation as a solution to this stagnation problem and is demonstrated in this paper. (C) 2004 Elsevier Ltd. All rights reserved.