Scattering processes in terahertz InGaAs/InAlAs quantum cascade lasers

摘要

We report InGaAs/InAlAs based terahertz quantum cascade lasers with a short, bound-to-continuumndesign. These lasers operate at 3.1 THz up to a 115 K and emit 19 mW of peak optical power at 10nK. Devices with a modified waveguide lase up to 122 K with reduced power of 4 mW. The uppernstate lifetime was computed assuming alloy, interface roughness and longitudinal-optical u0002LOu0003nphonon scatterings. Comparison with experiment suggests that the elastic scattering processes limitnthe lifetime at low temperature while the inelastic LO-phonon scattering becomes the dominantnscattering mechanism at elevated temperature. Magnetotransport measurements provide additionalnevidence which supports the role of elastic scattering processes at low temperatures. © 2010nAmerican Institute of Physics. u0004doi:10.1063/1.3504251