MANUFACTURE OF POSITIVE INDEX WAVEGUIDE

摘要

A process of preparing a laterally confined positive index waveguide is disclosed in which a monocrystalline substrate comprised of a III-V compound is provided having adjacent one major surface monocrystalline gallium aluminum arsenide having a resistivity greater than 10<5> ohm-cm. A protective layer is provided on the substrate, and a channel is opened in the substrate to expose an unprotected portion of the substrate. A waveguide region is formed by selectively depositing epitaxially on only the unprotected portion of the substrate at least one III-V compound of a higher refractive index than the substrate monocrystalline gallium aluminum arsenide. Epitaxial deposition is terminated when the waveguide region forms with the one major surface an overall planar surface, and at least one layer bridging the substrate and the waveguide region is deposited on the planar surface.