Distributed-feedback GaInAs∕AlAsSb quantum-cascade lasers operating at 300K

Short-wavelength (λ∼4μm) single-mode distributed-feedback GaInAs∕AlAsSb quantum-cascade lasers operating in pulsed mode up to room temperature (300K) have been demonstrated by etching an index-coupled first-order distributed-feedback grating into the upper GaInAs separate confinement layer. The temperature-dependent wavelength shift of the distributed-feedback lasers is −0.14cm−1∕K (0.238nm∕K). For devices with a size of 18μm×2.9mm mounted epilayer-up with as-cleaved facets, a maximum peak power per facet of 840mW has been achieved at 77K and 4mW at 300K. The characteristic temperature T0 of the threshold current density is 105K.