Interband cascade lasers: progress and outlook

摘要

Type-ⅡInterband cascade lasers combine interband optical transitions with interband tunneling to enable the cascading of type-Ⅱ quantum well active regions. This combination allows for low threshold current densities and high external slope efficiencies, both of which are important for high temperature, high power operation. Experimental results have already demonstrated some of this potential including high differential external quantum efficiency (>600%), high peak output powers (～6 W/facet at 80 K), high cw power conversion efficiency (>32% at 80 K), and lasing above 315 K under pulsed conditions. However, cw operation at high temperature has not yet been achieved -present generation 3.6-μm-wavelength interband cascade lasers fail to operate under cw conditions at heat sink temperatures above ～214 K. Past performance highlights and recent advances are described, followed by a discussion of issues that continue to limit high temperature, cw performance. The outlook for improving device performance is presented, including a discussion of areas where further research is needed.