A new waveguide switch/modulator for integrated optics

A waveguide optical switch and/or modulator device is described that uses a single-mode waveguide version of the Mach-Zehnder interferometer. A mode selective branching waveguide is used for switching, and modulation can be accomplished without external polarizers in single-mode waveguides. The operation of a 1×2 switch fabricated by diffusion techniques in ZnSe is described.