Quantum-cascade lasers operating in continuous-wave mode above 90 °C at λ∼5.25 μm -: art. no. 051105

We report on the design and fabrication of lambda similar to 5.25 mu m quantum-cascade lasers (QCLs) for very high temperature continuous-wave (cw) operation. Cw operation is reported up to a maximum temperature of 90 degrees C (363 K). Cw output power is reported in excess of 500 mW near room temperature with a low threshold current density of 1.4 kA/cm(2) at 298 K. Room temperature average power of over 540 mW is reported at 50% duty cycle. A high thermal conductance (G(th)) of 340 W/K cm(2) is reported for cw QCLs. A finite element thermal model is used to investigate the G(th) and maximum cw operating temperature of the QCLs. (c) 2006 American Institute of Physics.