Indirectly Pumped 3.7 THz InGaAs/InAlAs Quantum-Cascade Lasers Grown by Metal-Organic Vapor-Phase Epitaxy
Date of this Version8-27-2012
Optics Express Vol. 20, No. 18, 20647-20658. 27 August 2012
Device-performances of 3.7 THz indirect-pumping quantum- cascade lasers are demonstrated in an InGaAs/InAlAs material system grown by metal-organic vapor-phase epitaxy. The lasers show a low threshold-current-density of ~420 A/cm2 and a peak output power of ~8 mW at 7 K, no sign of parasitic currents with recourse to well-designed coupled-well injectors in the indirect pump scheme, and a maximum operating temperature of Tmax~100 K. The observed roll-over of output intensities in current ranges below maximum currents and limitation of Tmax are discussed with a model for electron-gas heating in injectors. Possible ways toward elevation of Tmax are suggested.
Nanoscience and Nanotechnology