$GaAs/Al0.15Ga0.85As$ terahertz quantum cascade lasers with double-phonon resonant depopulation operating up to 172 K

We report the design and performance of $GaAs/Al0.15Ga0.85As$ terahertz quantum cascade lasers with double-phonon resonant depopulation and a vertical lasing transition. Devices were processed into gold-clad double-metal waveguides. Lasing at 3 THz was observed up to a heat-sink temperature of 172 K, which compares favorably with the performance of single-phonon resonant depopulation devices based on vertical lasing transitions. These results demonstrate that terahertz quantum cascade lasers based on double-phonon depopulation designs may be a viable alternative to single-phonon depopulation designs for achieving high-temperature operation.