Process to Mitigate Catastrophic Optical Damage to Quantum Cascade Lasers

In this program, we will develop solutions to optimize QCL fabrication processes, such as facet passivation and high thermal conductivity coatings, that will mitigate the reliability issues for high power QCL applications. In phase I, we will first evaluate all concepts and efforts that have been largely investigated for GaAs based high power diode lasers and transfer the knowledge to InP based QCLs. We will develop models to describe the positive feedback loop responsible for the thermal runaway in QCLs. We will perform experimental data collection to refine the model via study of immediate (microsecond scale) damage at high power level, long term degradation, and defects formation analysis. Based on our findings we will devise a fabrication process that alleviates the effects that lead to COD in QCL.