Strained InGaAs/AlGaAs/GaAs-quantum cascade lasers

We report on the realization of a quantum cascade laser based on strained In0.04Ga0.96As/Al0.33Ga0.67As/GaAs grown on GaAs substrate using molecular beam epitaxy. Lasing at 10.40 μm and at 9.45 μm was achieved with a good temperature performance showing a T0,2=112 K between 125 and 200 K and a maximum working temperature exceeding T=200 K. Between 78 and 130 K a considerably higher T0,1 of 291 K is found. The decreasing T0 with higher temperatures is due to misalignment of the injector with the upper laser level at elevated temperatures, thermal activation of tunneling of carriers above 130 K, and increasing carrier leakage from the injector into the continuum.