Performance and degradation characteristics of blue–violet laser diodes grown by molecular beam epitaxy

This paper reports the state of the art performance for blue― violet laser diodes (LD) grown by molecular beam epitaxy. Improvements in device design and growth have resulted in a threshold current density of 3.6 kA/cm 2 , which translates into improved cw lifetime of up to 42 hours. Reducing the internal loss resulted in a high cw slope efficiency of 1.08 W/A and a maximum cw output power of 145 mW. To obtain a better understanding of the LD failure mechanism, degraded LDs were analysed using surface mapping techniques such as photoluminescence and electroluminescence on a micrometric scale, which allows the identification of failure regions. These measurements revealed increased nonradiative recombination in localized regions and increased current injection nonuniformities as possible mechanisms for LD performance degradation after aging.