A high-speed hybrid optical–digital correlator system was designed, constructed, modeled, and demonstrated experimentally. This correlator is capable of operation at approximately 3000 correlations/s. The input scene is digitized at a resolution of 512 × 512 pixels and the phase information of the two-dimensional fast Fourier transform calculated and displayed in the correlator filter plane at normal video frame rates. High-fidelity reference template 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 reference data set with the input scene within one frame period. A high-speed CCD camera is used to capture the correlation-plane image, and rapid correlation-plane processing is achieved with a parallel processing architecture.
© 1999 Optical Society of America
James H. Sharp, Nick E. MacKay, Pei C. Tang, Ian A. Watson, Brian F. Scott, David M. Budgett, Chris R. Chatwin, Rupert C. D. Young, Sylvie Tonda, Jean-Pierre Huignard, Tim G. Slack, Neil Collings, Ali-Reza Pourzand, Marcus Duelli, Aldo Grattarola, and Carlo Braccini, "Experimental Systems Implementation of a Hybrid Optical–Digital Correlator," Appl. Opt. 38, 6116-6128 (1999)