Nitride Laser Diodes With Nonepitaxial Cladding Layers

Semiconductor laser diodes (LDs) typically use lattice-matched epitaxial layers as waveguide cladding materials. We describe a new LD architecture in which the upper cladding layer is replaced with an evaporated or sputtered nonepitaxial material. Designs and results are presented for 415-nm InGaN LDs 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 nonepitaxial 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.