High-performance, aluminum-free optically-pumped mid-IR semiconductor lasers

We demonstrate that it is possible to create a mid-infrared laser structure which is free of aluminum by using GaSb as the optical cladding material in an integrated absorber laser structure. Based on previously published data at shorter wavelengths, the refractive index of the InGaAsSb used in the IA QW laser structures is extrapolated to be higher than that of GaSb This index step is an order of magnitude smaller than when using the more conventional AlAsSb as the optical cladding.