Reliability of ensembles multi-stripe laser diodes

As GaAs based laser diode reliability improves, the optimum architecture for diode pumped configurations is continually re-examined. For such assessments, e.g. bars vs. single emitters, it is important to have a metric for module reliability which enables comparisons that are the most relevant to the ultimate system reliability. We introduce the concept of mean time between emitter failures (MTBEF) as a method for characterizing and specifying the reliability of multi-emitter pumps for ensemble applications. Appropriate conditions for an MTBEF model, and the impact of incremental changes of certain conditions on the robustness of the model are described. In the limit of independent random failures of individual emitters as the dominant failure mechanism it is shown that an ensemble of multi-emitter modules can be modeled to behave like an ensemble of single emitter modules. The impact of thermal acceleration due to failed emitters warming other emitters on a shared heat-sink is considered. Data taken from SP built multi-emitter devices bonded with AuSn on CTE matched heat-sinks is compared with the MTBEF model with and without correction for the thermal acceleration effect.