Abstract:

The authors report the fabrication of high-power strained quantum cascade lasers working in continuous mode above 370 K. The devices, processed in narrow buried heterostructures, were grown by low-pressure metal organic vapor-phase epitaxy. Continuous wave output power as high as 312 mW at 300 K was obtained at a wavelength of 5.29 mu m from a 3.25 mm long, 7.5 mu m wide laser with a high-reflectivity back facet coating. The slope efficiency was in excess of 1.5 W/A and the power conversion efficiency reached almost 5%.