Development of low-threshold current stripe lasers from GaInAsSb/GaAlAsSb DH wafers emitting at 2.2 μm

Abstract

We report the Gao.861ii0.i4Aso.i3Sbo.87 room temperature refractive index value obtained from direct reflectivity measurements and also estimated from laser transversefar field pattern measurements. The value n = 3.78 obtained is higher than previous theoretical calculations and is high enough to support a good optical confinement in DII lasers with 27% Al in the confining layers. We also show that the active layer low resistivity gives the main contribution to the high threshold current (Ith) for narrow stripe lasers. This is partly solved by making the active region n-type. The minimum 'th obtained for n-type active layer lasers was 29OmA compared to 800mA for p-type active layer lasers, the broad area threshold current being the same (3kA/cm2) in both cases.