Quantum-cascade lasers operating in continuous-wave mode above 90°C at λ∼5.25μm

Abstract

We report on the design and fabrication of λ∼5.25μm quantum-cascade lasers (QCLs) for very high temperature continuous-wave (cw) operation. Cw operation is reported up to a maximum temperature of 90°C (363K). Cw output power is reported in excess of 500mW near room temperature with a low threshold current density of 1.4kA∕cm2 at 298K. Room temperature average power of over 540mW is reported at 50% duty cycle. A high thermal conductance (Gth) of 340W∕Kcm2 is reported for cw QCLs. A finite element thermal model is used to investigate the Gth and maximum cw operating temperature of the QCLs.