A paraxial diffractive element is defined by a signal wave which is specified in a window of finite extent. The iterative Fourier transform algorithm is a well-known method to iteratively encode paraxial diffractive elements by making use of parameters of freedom. However, the algorithm suffers from a slow convergence if the parameters of freedom are limited. Thus, there is a demand for more efficient encoding strategies. Fienup considered to use descent methods for solving phase-retrieval problems which turned out to be very efficient. In this paper, we modify his theory that it can be applied for the design of diffractive phase elements. Computer simulations document that descent methods have a clearly better performance than the iterative Fourier transform algorithm.

Date Published: 20 April 1995
PDF: 10 pages
Proc. SPIE 2404, Diffractive and Holographic Optics Technology II, (20 April 1995); doi: 10.1117/12.207489

Published in SPIE Proceedings Vol. 2404:
Diffractive and Holographic Optics Technology II
Ivan Cindrich; Sing H. Lee, Editor(s)