Demonstration of high-performance 10.16 <i>µ</i>m quantum cascade distributed feedback lasers fabricated without epitaxial regrowth

We present measurement results on high-power low threshold quantum cascade distributed feedback lasers emitting infrared radiation at 10.16<i>µ</i>m. A lateral current injection scheme allowed the use of a strongly coupled surface grating without metal coverage and epitaxial regrowth. Although this design resulted in a simplified processing, the fabrication of high performance devices was demonstrated. The laser emitted 230 mW of pulsed power at 85 K, and 80 mW at room temperature. Threshold current densities of 1.85 kA/cm² at 85 K and 5.4 kA/cm² at room temperature were observed. Since the spectrum showed single mode behavior for all temperatures and power levels of the operating range, this device will be ideal for optical sensor applications.