Wave guide optimization for homoepitaxial laser diodes

Abstract

GaN-based high power laser diodes in the violet spectral range are demanding for conductive substrates with a lower thermal resistance than the commonly used sapphire. The only feasible approach to this goal is homoepitaxy on GaN wafers produced from thick GaN layers grown by hydride vapour phase epitaxy. One drawback of GaN substrates is the high refractive index and therefore it acts as an parasitic wave guide. In this paper we will discuss the optimization of the wave guide and the n-side cladding layer.