Abstract: The invention relates to systems and methods for optical Fourier processing and logic operations based on the discovery that the photoinduced anisotropy of photochromic materials such as bacteriorhodopsin, organic fulgides, azo and fluorescent dyes, phycobiliproteins, rhodopsins, and their analogs, is dependent on the intensity of a polarized actinic beam that illuminates the material and the intensity profile of one or more input beams. This intensity dependence can be used to implement a simple, real-time, self-adaptive optical processing, i.e., spatial filtering, system for Fourier processing of optical input images. This optical processing system can be used to process a wide variety of optical input images, from projected still images to live motion picture images.

Abstract: All-optical devices, e.g., optical switches and modulators, and logic gates such as optical AND and OR gates, that include photochromic materials having first and second stable states, such as bacteriorhodopsin, organic fulgides, azo and fluorescent dyes, phycobiliproteins, rhodopsins, and their analogs, irradiated in a four-wave mixing geometry, are described. These devices can be used in a wide variety of systems, such as, e.g., optical signal processors and optical computers.