Fabrication of single-crystal semiconductor optical waveguides by solid-state diffusion

Abstract

Optical surface waveguides have been fabricated by diffusing selenium into single‐crystal CdS substrates to produce graded‐composition CdS_xSe_1−x crystals. Planar guides which confine a beam in one dimension and guides produced by masked diffusion capable of two‐dimensional beam confinement have been obtained. Evidence of guiding of light from a HeNe laser is provided by photographs and by measurements of spatial intensity profiles. Losses are estimated to be 10–15 dB/cm for one‐dimensional guides and 30–40 dB/cm for two‐dimensional guides.