Superluminescence diodes at 2.4 microns from GaInAsSb/AlGaAsSb quantum well heterostructures for optical glucose sensing

High power, broadband light sources emitting in the 2-2.5 um wavelength range important for optical sensing of important biomolecules in aqueous solutions such as glucose. Here we demonstrate and analyze superluminescent diodes with output centered at 2.4 ums (range ~2.2-2.5 ums) from GaInAsSb/AlGaAsSb quantum wells in a separate confinement structure. Quasi-continuous wave output of 1 mW is achieved at room temperature for 40m x 2mm devices. Superluminescence is evidenced in superlinear growth, spectral narrowing, and angular narrowing of light output with increasing current injection. The output is analyzed and modeled with semiconductor rate equations, and by varying parameters, potential routes for future improvements are explored, such as additional Auger suppression and photonic mode engineering.