InGaAs/AlAsSb/InP quantum cascade lasers operating at wavelengths close to 3 μm

The authors report the realization of short wavelength (3.05 mu m <=lambda <= 3.6 mu m) InP lattice-matched In0.53Ga0.47As/AlAs0.56Sb0.44 quantum cascade lasers (QCLs). The highest-performance device displays pulsed laser action at wavelengths between 3.4 and 3.6 mu m, for temperatures up to 300 K, with a low temperature (80 K) threshold current density of approximately 2.6 kA/cm(2), and a characteristic temperature of T-0 similar to 130 K. The shortest wavelength QCL (lambda approximate to 3.05 mu m) has a higher threshold current density (similar to 12 kA/cm(2) at T=20 K) and operates in pulsed mode at temperatures up to 110 K. (c) 2007 American Institute of Physics.