Room Temperature Low-Threshold Mid-Infrared Quantum Cascade Lasers

We report room temperature low current density of InP-based AlInAs/InGaAs quantum cascade laser (QCL). For a 7.66-μm QCL, the threshold current density of 1.7 kA/cm
²
at 300 K, pulsed output power of 800 mW at 80 K, and continuous-wave (CW) output power of 13 mW at 135 K are achieved. An 8.91-μm QCL comprised 100 stage active region operaring up to 320 K in pulsed mode also presented.