Nitride laser diodes with non-epitaxial cladding layers

Abstract

Semiconductor laser diodes typically use lattice-matched epitaxial layers as waveguide cladding materials. We describe a new laser diode architecture in which the upper cladding layer is replaced with an evaporated or sputtered non-epitaxial material. Designs and results are presented for 415 nm InGaN laser diodes that use indium tin oxide, silver, or a silver-palladium-copper alloy as the cladding material, chosen because the material exhibits requisite optical and electrical properties. The non-epitaxial cladding layer offers several advantages, such as eliminating the need to expose vulnerable InGaN active layers to the high temperatures required for growing conventional p-AlGaN cladding layers subsequent to the active layer growth.