Low Power Consumption Distributed-Feedback Quantum Cascade Lasers Operating in Continuous-Wave Mode above 90^\circ\!C at \lambda \sim7.2μm

We report on the design and fabrication of \lambda\sim 7.2 μm distributed feedback quantum cascade lasers for very high temperature cw operation and low electrical power consumption. The cw operation is reported above 90^\circ\!C. For a 2-mm-long and 10-μm-wide laser coated with high-reflectivity on the rear facet, more than 170 mW of output power is obtained at 20^\circ\!C with a threshold power consumption of 2.4 W, corresponding to 30 mW with a threshold power consumption of 3.9 W at 90^\circ\!C. Robust single-mode emission with a side-mode suppression ratio above 25 dB is continuously tunable by the heat sink temperature or injection current.