Broadband heterogeneous quantum cascade lasers

Abstract

Heterogeneous quantum cascade lasers have emerged as an important broadband radiation source for mid-infrared spectroscopy and sensing. Multiple quantum cascade stages with discrete peak wavelengths are grown together in single active region to have a broad gain. Different wavelength laser can be chosen by appropriate feedback mechanism. Heterogeneous strain-balanced Al0.63In0.37As/ Ga0.35In0.65As/Ga0.47In0.53As quantum cascade lasers, having 5 and 6 quantum cascade stages respectively, has been demonstrated with gain between 6.2-9.9 μm and 5.9-10.9 μm in mid-infrared region.