Optical waveguides by diffusion in II-VI compounds

Planar optical waveguides have been made by sealed ampoule diffusion of Cd and Se into ZnS and Cd into ZnSe. Three-dimensional diffused guides of Cd-diffused ZnSe have been made by using a masking layer of evaporated oxidized SiO, which was shadowed with silica or glass fibers or copper wire. Structures 50 and 160 μm wide and 10 μm deep with severely etched surfaces yielded losses of 10 dB/cm. Suppression of thermal etching in small-index-gradient guides 10 μm wide by 3 μm deep gave losses of less than 3 dB/cm.