High peak-power (10.5 W) GaInAs/AlGaAsSb quantum-cascade lasers emitting at lamda ~ 3.6-3.8 µm

High peak-power operation of quaternary-barrier GaInAs/AlGaAsSb quantum-cascade lasers emitting at lambda about 3.6-3.8 µm is reported. With as-cleaved facets, the lasers (18 µm x 2.7 mm) emit a maximum peak power of 8.2 W per facet at 77 K. When applying a high-reflection coating to the back facet, a maximum peak power emitted from the front facet of 10.5 W at 77 K has been obtained for an 18 µm x 2.0 mm device. The lasers operate in pulsed mode up to 340 K, and their emission wavelength shifts from 3.65 µm at 77 K to 3.79 µm at 300 K.