title: Optical applications of von Neumann's alternating-projection theorem.
abstract: The previous work of Gerchberg [Opt. Acta 21, 709 (1974)], Papoulis [IEEE Trans. Circuits Syst. CAS-22, 735 (1975)], Youla [IEEE Trans. Circuits Syst. CAS-25, 694 (1978)], and Stark et al. [J. Opt. Soc. Am. 71, 735 (1981)] on image restoration is presented in a generalized setting. New examples using three projections are given. The method is used to solve the general problem of diffraction by a perfectly conducting plane screen of arbitrary configuration.
authors.forename: W D
authors.initials: WD
authors.lastname: Montgomery