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 188 K. Threshold current densities of 950 A/cm(2) and output powers of 125 mW are measured at 80 K, while 3 mW of continuous output power are measured at 180 K, with a threshold of 2.5 kA/cm(2). In pulsed mode, peak output powers of more than 0.4 W were obtained at 80 K and of 160 mW at 300 K with thresholds of 700 A/cm(2) and 2.75 kA/cm(2), respectively. (C) 2004 American Institute of Physics.