Optical crossbar switching network

Claim 1

An optical switching network of the type employing a plurality of optical crosspoints to provide connections in an NxN network of optical waveguide communication channels, characterized in that a first plurality N of the optical waveguide channels are parallel to each other and define a first plane, a second plurality N of optical waveguide channels are parallel to each other and define a second plane which is parallel to said first plane, said waveguide channels in said first plane crossing over said waveguide channels in said second plane without intersection, each region of closest approach of one waveguide channel from said first plurality N of waveguide channels to a second waveguide channel in said second plurality N of waveguide channels defining a proposed switching crosspoint, and further characterized by including at each of the proposed switching crosspoints a first beam-to-guide (grating-type) coupler to couple the modulated optical energy from said one waveguide channel of the first plurality of waveguide channels, and laterally disposed therefrom in a direction chosen to define the optical communication path between waveguide channels a second beam-to-guide coupler to couple the energy from the first coupler into said second waveguide channel of the second plurality of waveguide channels, each of said first and second couplers being controllable between noncoupling and coupling conditions with respect to its related waveguide channel.