Device characteristics of double heterostructure lasers with Al
0.4Ga
0.6As confinement layers and GaAs
0.99Sb
0.01active layers are presented. Average emission wavelengths have been increased from 0.87 μm for undoped active layers to 0.88 μm for

cm
-3Ge doped active layers with a "wash" melt preceding the growth of the active layer and to 0.89 μ for

cm
-3Mg doped active layers grown following a "wash" melt. Threshold currents for lasers from 21 wafers are examined for several growth conditions and compared with Al
0.08Ga
0.92As active layer devices. Device resistance, external quantum efficiency, device degradation, and pulsed and CW threshold currents as a function of temperature are also discussed.