A high-power continuous-wave (CW) operation of distributed-feedback quantum-cascade lasers using a buried grating with epitaxial regrowth up to temperatures of above 60 °C is demonstrated. For a high-reflectivity-coated 13 μm -wide and 3 mm -long cavity, CW output powers of 135 mW at 25 °C and still 37 mW at 60 °C are obtained. The device exhibits a CW threshold current density of 1.1 kA cm2, a maximum CW wall-plug efficiency of 1.48% at 25 °C, and a characteristic temperature of 177 K in pulsed mode. Single-mode emission near 4.8 μm with a side-mode suppression ratio of >30 dB and a tuning range of ∼8.1 cm-1 (i.e., tunability of 0.18 cm-1 K) in the temperature range from 15 to 60 °C is observed.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)