High-temperature, high-power, continuous-wave operation of buried heterostructure quantum-cascade lasers

The continuous wave (cw) operation of a 6 μm quantum-cascade laser (QCL) up to 333 K was analyzed. A narrow ridge waveguide, buried heterostructure geometry and a thick electroplated Au layer were used for improved heat dissipation. The optical output powers of 446 mW at 293 K, 372 mW at 298 K and 30 mW at 333 K were obtained for the cw operation. It was shown that a room-temperature cw wall-plug efficiency of 3.69% was reported for a drive current of 1.03 A, a bias voltage of 9.8 V, and an optical output power of 372 mW. The results show that the R _th of the device was 2.99-7.8 K/W between 293 and 333 K.