Recently we reported on AlInGaAs/AlGaAs strained quantum-well lasers, with emission wavelengths ranging from 890 to 785 nm, that had threshold current densities as low as 103 A/cm2 and differential quantum efficiencies as high as 90%.1 Potentially, emission wavelengths as short as 660 nm can be achieved by increasing the Al content of the active layer. Because the density of states is reduced by compressive strain, these lasers can have lower threshold current densities than AlGaAs/AlGaAs lasers. In addition, the incorporation of In in the active layer is expected to improve the reliability of the new lasers, since the propagation of defects should be retarded because the In atom is larger than the Ga, Al, and As atoms, which are almost the same size. In this paper, we report cw operation of AlInGaAs/AlGaAs GRIN-SCH SQW lasers with output power as high as 3.5 W/facet.
© 1991 Optical Society of AmericaPDF Article