Simple patterns consisting of three spots (V and Γ) have been recognized by dividing, shifting, and recombining beams onto bistable ZnS interference filters. This experiment demonstrates AND-gate operation, cascading, and a moderate amount of parallelism, but a laser power of several watts was required and the response times were several milliseconds. An associative memory for fingerprint identification has been constructed using a VanderLugt correlator and an interference filter as a reflective thresholding device.
© 1988 Optical Society of America
L. Wang, V. Esch, R. Feinleib, L. Zhang, R. Jin, H. M. Chou, Robert W. Sprague, H. Angus Macleod, G. Khitrova, Hyatt M. Gibbs, Kelvin Wagner, and Demetri Psaltis, "Interference filters as nonlinear decision-making elements for three-spot pattern recognition and associative memories," Appl. Opt. 27, 1715-1720 (1988)