Strained InGaAs/AlGaAs/GaAs-quantum cascade lasers

We report on the realization of a quantum cascade laser based on strained I n0.04Ga0.96As/Al0.33Ga0.67As/GaAs grown on GaAs substrate using molecular b eam epitaxy. Lasing at 10.40 mu m and at 9.45 mu m was achieved with a good temperature performance showing a T-0.2 = 112 K between 125 and 200 K and a maximum working temperature exceeding T = 200 K. Between 78 and 130 K a c onsiderably higher T-0.1 of 291 K is found. The decreasing T-0 with higher temperatures is due to misalignment of the injector with the upper laser le vel at elevated temperatures, thermal activation of tunneling of carriers a bove 130 K, and increasing carrier leakage from the injector into the conti nuum. (C) 2000 American Institute of Physics. [S0003-6951(00)04723-9].