Design of single-mode narrow-bandwidth thermal emitters for enhanced infrared light sources

We design efficient thermal emitters based on intersubband transitions (ISB-Ts) in quantum wells and two-dimensional photonic crystal (PC) slabs that have single-mode, very narrowband emission with high emissivity. Our design strategy involves positioning a single isolated mode of the PC within the absorption range of the ISB-T, where the mode's radiation rate is precisely matched with the absorption rate of the ISB-T. The optimized design for this class of thermal emitters has a single-peak emission with a quality factor of similar to 600, an emissivity of similar to 0.9, and a radiation divergence cone of similar to 20 degrees, surpassing, by a large margin, the performance of previous designs. We also demonstrate, for practical application purposes, that the required input power for our best-performing emitter to reach a given temperature threshold is less than a factor of 200 compared to that of a blackbody. (C) 2012 Optical Society of America