Abstract: A modulator and switch for optical energy includes an optical waveguide dning a path for the propagation of optical energy, a source of microwave energy, and at least one strip transmission line disposed in co-directional proximity relative to the optical waveguide and connected to the source of microwave energy. The strip transmission line is designed to have dimensions and dielectric constants for producing a propagation velocity of the microwave energy substantially equal to the propagation velocity of the optical energy in the optical waveguide. A suitable microwave load is connected to the transmission line for completing an electrical circuit with the source of microwave energy.

Abstract: Light energy is coupled between a first optical path including a first chel optical waveguide defined by a selected material diffused into a substrate and a second optical path including a second channel optical waveguide defined by a selected material diffused into the same substrate. The two channel optical waveguides are disposed in substantially non-coupling, co-extensive proximity on the substrate. An area of the same substrate between the two channel optical waveguides is diffused with a material for inducing a determinable degree of coupling between the two optical waveguides but is of insufficient depth of diffusion to support light wave propagation in and of itself in the manner of an optical waveguide. By selectively and controllably varying the amount of diffusion between the channel optical waveguide optimum efficiency of coupling may be achieved therebetween with a desirably high degree of precision through the use of relatively simple and inexpensive fabrication techniques.

Abstract: Coextensive first and second optical waveguides are disposed with substantially uniform periodic variations in spatial separation including repetitive sections of close proximity which will permit optical coupling therebetween. The first optical waveguide has a different optical length (i.e., different light energy propagation characteristics) than the second optical waveguide. Due to the different effective optical lengths of the two waveguides between contiguous sections of close proximity where optical coupling may take place, light energy of a determinable frequency propagated along one of the waveguides is substantially all coupled into the other optical waveguide in the course of propagating along a determinable number of the repetitive sections; light energy of all other frequencies is effectively phase cancelled and thus inhibited from being coupled between the two optical waveguides.