We have investigated a novel coherent optical correlator architecture for both recognizing and distinguishing between a plurality of patterns using only a single fixed binary phase-only matched filter, referred to here as a multiplexed filter. In order to utilize the filer space effectively we have introduced a novel spread spectrum technique for coding the input patterns, so called overlay encoding, suing a random high frequency binary phase-only mask. We have shown how standard optimization techniques can be used to design a multiplexed filter, which is capable of producing a set of codes in the output plane when the corresponding elements of a set of input patterns are presented in the input plane. The theoretical analysis has been verified experimentally using commercially available ferroelectric liquid crystal spatial light modulators.

Date Published: 27 March 1997
PDF: 4 pages
Proc. SPIE 3073, Optical Pattern Recognition VIII, (27 March 1997);

Published in SPIE Proceedings Vol. 3073:
Optical Pattern Recognition VIII
David P. Casasent; Tien-Hsin Chao, Editor(s)