Feedback-Induced Failure of High-Power Diode Lasers

Catastrophic failure of diode pumps in laser systems exhibiting back-irradiance is a common occurrence yet poorly understood. Prior paper has established boundaries for time-zero failures, but these results cannot be used to deduce safe back-irradiance levels for long-term reliable operation. In this paper, a framework to describe the impact of back-irradiance on the reliability of diode pumps is established. The root-cause of back-irradiance induced failure is identified as thermal in nature. The approach follows conventional reliability methodologies by treating the parameters of back-irradiance as stressors, which accelerate failures.