Temperature dependence of threshold current for 1.8 to 2.3 μm (AlGaIn)(AsSb)-based QW diode lasers

We report on the temperature dependence of threshold current for ridge waveguide Ga_1-xIn_xAs_ySb_1$ -_y/Al_0.29Ga_0.71As_0.02Sb _0.98 triple-QW diode lasers grown by MBE on GaSb. In and As contents in the QWs were in the 0.16⩽x⩽0.30 and 0⩽y⩽0.15 range, respectively, resulting in different strain states, band gap energies and band offsets. Devices with lasing wavelengths extending from 1.8 to 2.3 μm at room-temperature were tested in cw mode. Characteristic temperatures for the threshold current ranged from T₀=172 K at 1.94 μm to T₀=93 K at 2.23 μm and T₀=52 K at 2.34 μm for the 200 to 280 K temperature interval. The pronounced drop in T₀ is associated with a significant decrease in the valence band offset from 0.27 eV to 0.22 eV and 0.14