Abstract

Spatially incoherent correlators¹ are advantageous compared with coherent correlators because diffuse or self-luminous objects can be used directly as inputs without converting them to coherent light inputs. In addition, incoherent light systems are less sensitive to the lateral positioning of the filter. For the coherent correlator, it has been shown² that in certain cases a phase-only filter can provide better correlation results, i.e., narrower correlation peaks and higher signal to noise ratio. We are investigating in this work ways for implementing the effect of a phase-only filter in incoherently illuminated set-up. Although two different filters will be needed for implementing equivalent complex functions, the final behavior of the system will be like that obtainable from coherent phase-only filters. In addition, we might optimize the light efficiency by using phase-only aperture masks as matched filters. Computer simulations and experimental results were performed.

© 1992 Optical Society of America