Dual-Lasing Channel of a High-Temperature Terahertz Quantum Cascade Laser

Terahertz (THz) quantum cascade lasers (QCLs) are powerful coherent light sources covering the frequency range from 1.2 to 5.4 THz, but still suffer from operation temperatures below 200 K [1]. Beside the standard material system GaAs/AlGaAs novel material systems with lower effective electron masses were investigated to improve the operation temperature of THz QCLs. These materials include InGaAs and InAs based systems [2-4] which benefit from a higher optical gain but suffer from molecular beam epitaxy growth issues due to their very thin barrier layers.