Experimental systems implementation of a hybrid optical-digital correlator

A high-speed hybrid optical-digital correlator system was designed, constru cted, modeled, and demonstrated experimentally. This correlator is capable of operation at approximately 3000 correlations/s. The input scene is digit ized at a resolution of 512 x 512 pixels and the phase information of the t wo-dimensional fast Fourier transform calculated and displayed in the corre lator filter plane at normal video frame rates. High-fidelity reference tem plate images are stored in a phase-conjugating optical memory placed at the nominal input plane of the correlator and reconstructed with a high-speed acousto-optic scanner; this allows for cross correlation of the entire refe rence data set with the input scene within one frame period. A high-speed C CD camera is used to capture the correlation-plane image, and rapid correla tion-plane processing is achieved with a parallel processing architecture. (C) 1999 Optical Society of America.