EFFECTS OF SYSTEMATIC PHASE ERRORS ON PHASE-ONLY CORRELATION

The performance of phase-only optical correlators is usually reduced i f the filter-plane phase differs from that prescribed for the classica l matched filter. Current spatial light modulators, which frequently p roduce less than 2 pi phase modulation, and interface circuits, which quantize or incorrectly amplify signals placed on the spatial light mo dulator, both can produce systematic phase errors. We examine these ef fects using a model of correlation-peak. amplitude as a function of ph ase error. The correlation peak is reasonably approximated as the prod uct of an average of unity-amplitude error phasors multiplied by the a verage amplitude across the filter plane. The trends predicted by this new model compare favorably with computer simulations that use gray-s cale images.