Measuring and modeling quasicontinuous wave operation of quantum cascade lasers for enhanced average brightness

Abstract

Quasicontinuous wave operation of midinfrared quantum cascade lasers are shown to have increased average output power with good beam quality. The ability to enhance average power by a significant fraction of CW power motivates the development of a model to estimate and project performance at varying duty cycles based on a previously developed continuous wave power projection model. The model takes into account pulse to pulse changes in temperature profile to project a transient steady-state temperature distribution. This temperature distribution is used to project both peak and average power in agreement with measurements. Preliminary model projections suggest that high average brightness may be achieved using a reduced number of stages and a greater scaling of core width than would be permissible for CW lasing.