Advanced facet passivation for high-power edge-emitting laser diodes

The increased performance requirements for high-power Edge Emitting Laser Diodes (EELD) present serious challenges for laser manufacturing processes and quality. One of the primary failure mechanisms limiting the performance and reliability of GaAs and AlGaAs-based laser diodes is related to Catastrophic Optical Mirror Damage (COMD), which occurs at the output facet when the laser is operated at high power levels. The main cause of COMD is oxidation-related atomic-level defects at the laser diode facet, which act as sites for absorption and heating. This paper demonstrates that by tailoring the III-V material surface with a novel crystalline oxide process prior to mirror coatings, the EELD performance can be substantially increased. A dedicated high-performance laser passivation equipment is developed and tested on surface-sensitive quantum well test structures and ultimately on high aluminum content edge-emitting laser bar diodes.