Optical residue arithmetic computer having programmable computation

Abstract

An optical computer based on the residue number system employs a plurality of computational modules which may be programmed using electronic pulses to perform addition, subtraction, multiplication and division operations. Each module comprises an array of optical switches in the form of directional wave guide couplers interconnected by optical transmission paths to form a series of maps corresponding to a given modulus. The optical switches are arranged in rows and groups of rows may be selectively activated to adapt the module to perform various arithmetic operations. One residue is input to the module in the form of light pulses and is spatially arranged to automatically select the proper map to perform a desired function. The optical switches in each row thereof are electrically interconnected to a bi-stable electrical switch that simultaneously switches all of the logical switches in that row in accordance with a programming input pulse delivered to one of the bi-stable switches. The light output from the last row of optical switches correspond to the function of two residues whose function has been computed and is delivered in spatially oriented form. The inputs of the electrical switches associated with one module may be connected with the light output of another module so as to permit various functions, such as polynomials, to be computed using chain processing techniques. Arrangements for encoding, decoding, and scaling are also disclosed.