High performance short period superlattice digital alloy InSb/Ga_xIn_1−xSb laser emitting at 1.9 µm

For the first time, lasers with short period superlattice based quantum wells have successfully been fabricated and characterized on the (AlGaIn)(AsSb) material system. These new quantum wells are composed of alternating InSb/Ga(x)In(1-x)Sb layers with submonolayer thickness. Distributed-feedback lasers fabricated from the epitaxial layers emit in the wavelength range around 1.9 µm. Side mode suppression ratios over 35 dB and very low threshold currents of 23 mA were realized. The laser emission wavelength can be varied from 1.844 to 1.902 µm using grating periods between 255.0 and 263.8 nm.