Numerical simulation of 4 μm InGaAs/AlAsSb Quantum Cascade Lasers on InP Substrate

In order to improve the performance of InGaAs/AlAsSb QCLs, the simulation of In 0.53 Ga 0.47 As/AlAs 0.56 Sb 0.44 QCLs on InP substrate are presented and analyzed. Based on the theory of carrier transition in an injector/3-level/extractor system, the conduction band diagram of InGaAs/AlAsSb QCLs is simulated and the effect of the inject layer thickness on the gain property and characteristic temperature are discussed. The results illustrate that the emitting wavelength λ blueshifts along with the increase of the inject layer thickness. And when the injection barrier width is 2.3 nm, the λ of In 0.53 Ga 0.47 As/AlAs 0.56 Sb 0.44 QCLs is around 4μm and the characteristic temperature is up to 140 K, which is in good agreement with experimental results. This work confirms the great potential of InGaAs/AlAsSb materials for the realization of efficient mid-infrared wavelength QCLs and provides a new way to design these devices.