Terahertz quantum cascade lasers based on type II InGaAs/GaAsSb/InP

Abstract

We report the demonstration of a terahertz quantum cascade laser based on the In0.53 Ga0.47 As/ GaAs0.51 Sb0.49 type II material system. The combination of low effective electron masses and a moderate conduction band offset makes this material system highly suitable for such devices. The active region is a three-well phonon depopulation design and laser ridges have been processed in a double-metal waveguide configuration. The devices exhibit a threshold current density of 2 kA/ cm2, provide peak optical powers of 1.8 mW, and operate up to 102 K. Emission frequencies are in the range between 3.6 and 4.2 THz. © 2010 American Institute of Physics.