Temperature dependence of threshold current for 1.8 to 2.3 /spl mu/m (AlGaIn)(AsSb)-based QW diode lasers

We report on the temperature dependence of threshold current for ridge waveguide Ga/sub 1-x/In/sub x/As/sub y/Sb/sub 1$/ -/sub y//Al/sub 0.29/Ga/sub 0.71/As/sub 0.02/Sb/sub 0.98/ triple-QW diode lasers grown by MBE on GaSb. In and As contents in the QWs were in the 0.16/spl les/x/spl les/0.30 and 0/spl les/y/spl les/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 /spl mu/m at room-temperature were tested in cw mode. Characteristic temperatures for the threshold current ranged from T/sub 0/=172 K at 1.94 /spl mu/m to T/sub 0/=93 K at 2.23 /spl mu/m and T/sub 0/=52 K at 2.34 /spl mu/m for the 200 to 280 K temperature interval. The pronounced drop in T/sub 0/ is associated with a significant decrease in the valence band offset from 0.27 eV to 0.22 eV and 0.14.