Room-temperature far-infrared emission from a self-organized InGaAs/GaAs quantum-dot laser

Abstract
Far-infrared spontaneous emission at 300 K and lower temperatures, due to intersubband transitions in self-organized In0.4Ga0.6As/GaAs quantum dots, has been characterized. Measurements were made with a multidot layer near-infrared (∼1 μm) interband laser. The far-infrared signal, centered at 12 μm, was enhanced after the interband transition reached threshold at 300 K. The results are explained in terms of the carrier dynamics in the dots.