Low-threshold continuous-wave operation of quantum-cascade lasers grown by metalorganic vapor phase epitaxy

We report on the realization of InGaAs∕InAlAs quantum-cascade lasers grown by metalorganic vapor phase epitaxy operating in continuous wave with low-threshold current densities at temperatures as high as 188K. Threshold current densities of 950A∕cm2 and output powers of 125mW are measured at 80K, while 3mW of continuous output power are measured at 180K, with a threshold of 2.5kA∕cm2. In pulsed mode, peak output powers of more than 0.4W were obtained at 80K and of 160mW at 300K with thresholds of 700A∕cm2 and 2.75kA∕cm2, respectively.