4-PLANE SPACE-VARIANT FRESNEL-TRANSFORM OPTICAL PROCESSOR WITH A RANDOM-PHASE ENCODER

We introduce a four-plane Fresnel-transform space-variant optical proc essor consisting of an input plane and two filter planes. One filter m ask is programmable with a spatial light modulator. The second filter mask is a fixed random binary phase array with a known pseudorandom di stribution of pixels. The order of the masks can be interchanged, givi ng different output characteristics. In one case the Horner efficiency of the correlator increases dramatically. In the other case the edge enhancement of the output image is removed. We discuss the theory for this general processor and its implementation with phase-only masks. W e present experimental results when a binary magnetooptic spatial ligh t modulator was used. (C) 1996 Optical Society of America