Electro-optical switching apparatus

Claim 1

Optical switching apparatus for optically coupling at least one photo-emitter circuit of a plurality of such photo-emitter circuits disposed as an emitting matrix to at least one circuit of a plurality of photo-receiver circuits disposed as a receiving matrix, comprising: a plurality of individually and simultaneously addressable photo-emitter circuits; a plurality of selecting matrices, one such selecting matrix associated with each photo-emitter circuit, for receiving and selectively transmitting, respectively, light emitted by the photo-emitter circuit associated therewith, each of said selecting matrices including: a first polarizer for polarizing light received by said matrix, a layer of electro-optical material for transmitting light polarized by said first polarizer, said layer having first and second faces, a first plurality of transparent strip electrodes parallel to each other and disposed on said first face, a second plurality of transparent strip electrodes parallel to each other but crossed with reference to said first plurality of electrodes said second plurality of electrodes being disposed on said second face and defining with said first plurality of electrodes a plurality of crossing points whereat the polarization of light transmitted by said layer can be locally rotated by selective activation of electrodes among said first and second pluralities, and a second polarizer having a direction of polarization that is crossed with respect to the direction of polarization of said first polarizer for selecting light transmitted by said layer at crossing points whereat the polarization of said transmitted light is rotated; a plurality of photo-receiver circuit matrices, each such matrix associated with a particular one of said photo-emitter circuits and a particular one of said selecting matrices, each such photo-receiver circuit matrix including a plurality of photo-receiver circuits; and means for forming images of said selecting matrices onto said plurality of photo-receiver circuits, so that light transmitted by each crossing point of one selecting matrix energizes one of said photo-receiving circuits, whereby light from any addressed photo-emitter circuit can be coupled to any photo-receiver circuit within the array of photo-receiver circuits associated therewith by energizing a selected cross point of the selecting matrix associated therewith.