Some methods for broadening the class of operations achievable by optical data processing systems

A variety of techniques for extending the domain of optical processors to nonlinear and space-variant operations is presented. Attention is given to: (1) the use of photographic film as a nonlinear element, (2) the application of nonlinear or saturable absorbers in the frequency domain, and (3) providing nonlinearities in coherent optical systems by means of the halftone process. Techniques for realizing linear space-variant filtering operations are described including the simultaneous control of position and direction of rays, holographic multiplexing, one-dimensional space-variant filtering, coordinate transformation processing, and matrix multiplication.