Optical switching device and parallel processing architecture

Abstract

A multiple-faced optical device comprising a light-responsive element having multiple faces, at least two of the faces constituting input faces for receipt of non-collinear light signals and at least one of the faces other than the input faces constituting an output face from which light signals transmitted through the light-responsive element are emitted. The light-responsive element is further configured to have optically-induced non-linear susceptibility to light signals transversely propagated through the light-responsive element such that at least one portion of the light-responsive element switches between two stable optical states in dependence on the total intensity of the light signals within the light-responsive element. The above-described optical device can be configured to perform various operations, such as AND/OR and INVERT/PASS logic operations, data line branching, signal time delay, and memory storage. An array of such devices provides parallel logic processing on a plurality of parallel optical data paths.

What is claimed is: 
     
       1. A multiple-face optical device comprising a light-responsive element having multiple faces, at least two of said faces constituting input faces for receipt of non-collinear light signals and at least one of said faces other than said input faces constituting an output face from which light signals transmitted through said light-responsive element are emitted; said light-responsive element being further configured to have optically-induced non-linear susceptibility to light signals transversely propagated through said light-responsive element such that at least one portion of said light-responsive element switches between two stable optical states in dependence on the total intensity of the light signals within said light-responsive element. 
     
     
       2. The optical device of claim 1 wherein said two optical states consist of an OFF state, wherein passage of light signals through said at least one portion is prevented, when said total intensity is less than a predetermined threshold; and an ON state, wherein passage of light signals transversely through said at least one portion is permitted, when said total intensity is not less than said predetermined threshold. 
     
     
       3. The optical device of claim 2 wherein said light-responsive element comprises one or more Fabry-Perot resonators. 
     
     
       4. Optical switch apparatus for providing storage or time delay transmission of an optical data signal comprising: a plurality of optical devices each comprising a light-responsive element having multiple faces, and being further configured to have first and second portions possessing substantially equal light sensitive non-linearly variable refractive indices, such that each portion switches from a first value to a second substantially different value in response to transversely propagated light signals within the portion having a total intensity equal to or greater than a threshold intensity; two of said faces respectively constituting a data signal input face and a first data signal output face for said first portion; said first and second portions being arranged to form an interface extending obliquely with respect to said data signal input face and said first data signal output face, such that a data signal having an intensity at least equal to said threshold intensity which is applied to the data signal input face of one of said optical devices will be reflected from the associated interface of the switch and outputted from the associated first data signal output face;   said plurality of optical devices being arranged to form a continuous loop data signal path whereby a data signal output from the first data output face of each optical device is received by the data signal input face of the next optical device in succession; and   at least one of said optical devices having a program signal input face and a second data signal output face, opposite said data signal input face, forming a part of the second portion thereof, such that a program signal having an intensity at least equal to said threshold intensity applied to said program signal input face causes a data signal applied to the associated data signal input face of said at least one of said optical devices to pass through the switch without substantial reflection at the associated interface thereof and to exit from the associated second data output signal face, rather than continuing to follow said continuous loop data signal path.   
     
     
       5. Optical switch multiple cell memory apparatus for simultaneous transfer of data from a plurality of cells in response to a single optical read signal comprising: a plurality of bistable optical switch means defining an array of memory locations arranged in a first plane, each of said switch means being switchable from a first state, wherein light propagating orthogonally to said first plane cannot pass through the switch means, in response to transversely propagating light signals within the switch means having a total light intensity which equals or exceeds a threshold intensity; and   a plurality of photosensitive elements arranged in a corresponding array in a second plane spaced from and aligned with said first plane so as to receive light signals produced by those ones of said switch means which are in said second state when said plurality of switch means is illuminated by an orthogonally directed optical read signal.   
     
     
       6. A programmable optical logic array device for parallel processing of at least one set of first and second non-collinear data signals along first and second data paths comprising: AND/OR optical device means controllable by a first optical program signal for selectively operating in an AND or an OR logic mode to produce corresponding first and/or second data output signals in dependence on the combination of data input signals present and the logic mode selected;   PASS/INVERT optical device means responsive to one of said first and second data output signals from said AND/OR optical device means and controllable by a second optical program signal for selectively operating in PASS or INVERT modes wherein, respectively, a PASS data output signal is produced in the same data path when said one of said first and second data output signals is present, and an INVERT data output signal is produced in a different data path when said one of said first and second data output signals is not present; and   BRANCHING optical device means responsive to said PASS and INVERT data output signals from said PASS/INVERT optical device means and controllable by a third optical program signal for selectively operating to transfer PASS and INVERT data output signals applied as inputs along the same data path as, or a different data path from, the data path on which the applied PASS/INVERT signal was travelling prior to transfer.   
     
     
       7. The programmable optical logic array of claim 6 wherein said AND/OR optical device means comprises a single cell light-responsive element having planar top and bottom faces and a polygonal shape defining multiple faces, two of said faces constituting input faces for receipt of said first and second data signals, respectively; two of said faces respectively opposite said input faces constituting output faces from which said first and second data output signals are respectively emitted; and one of said faces not constituting an input or an output face constituting a program signal input face for said first program signal; said light-responsive element being further configured to have optically-induced non-linear susceptibility to light signals transversely propagated through said light-responsive element such that said light-responsive element switches from an OFF state, wherein passage of light signals transversely through said light-responsive element is prevented, and an ON state, wherein passage of light signals transversely through said light-responsive element is permitted, when the total intensity of the light signals within said light-responsive element equals or exceeds a predetermined threshold, the value of said threshold relative to the intensities of said first and second data signals and said program signal being selected such that the intensities of none of said first and second data signals and said first program signal individually equal or exceed said threshold, but the combined intensities of any two of said first and second data signals and said first program signal at least equals said threshold, and said AND/OR switch means thereby operates in said AND logic mode when said first program signal is absent and in said OR logic mode when said first program signal is present.