Pulsed- and continuous-mode operation at high temperature of strained quantum-cascade lasers grown by metalorganic vapor phase epitaxy

We present the pulsed operation at room temperature of different strained InGaAs∕AlInAs quantum-cascade lasers grown by low-pressure metalorganic vapor-phase epitaxy. Devices based on a bound-to-continuum transition design have threshold current densities in pulsed mode as low as 1.84kA∕cm2 at 300K. Identical lasers grown at higher rate (0.5nm∕s) also have threshold current densities lower than 2kA∕cm2 at 300K. Buried heterostructure lasers based on a double phonon resonance design were operated in continuous mode up to 280K. Overall, the performance obtained from strained quantum cascade lasers deposited by metalorganic vapor-phase epitaxy are comparable with that of similar structures grown by molecular beam epitaxy.