GaN-based Violet-blue Laser Diodes

摘要

High power GaN-based laser diodes (LDs) are very desirable for various applications such as optical storage systems. We have obtained GaN films of low dislocation density using epitaxial lateral overgrowth (ELO) technique and the raised-pressure metalorganic chemical vapor deposition (RP-MOCVD) technique. Dislocation density of the improved GaN is about 10~7 cm~(-2). Optimized GaN-based LDs fabricated on the improved GaN films have operated up to 35mW without any kink. The lifetime is more than 500 hours with a constant power of 20 mW at 25 ℃ under continuous wave (CW) conditions. Furthermore, we have introduced buried-ridge laser diode structure in order to control the optical transverse mode. The features of the far field patterns (FFPs) of LDs with AlGaN burying layers indicate their controllability.