Low Power Consumption Distributed-Feedback Quantum Cascade Lasers Operating in Continuous-Wave Mode above 90°C at λ ∼ 7.2 μm*

We report on the design and fabrication of lambda similar to 7.2 mu m distributed feedback quantum cascade lasers for very high temperature cw operation and low electrical power consumption. The cw operation is reported above 90 degrees C. For a 2-mm-long and 10-mu m-wide laser coated with high-reflectivity on the rear facet, more than 170 mW of output power is obtained at 20 degrees C with a threshold power consumption of 2.4 W, corresponding to 30 mW with a threshold power consumption of 3.9W at 90 degrees 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.