Observation of stripe-direction dependence of threshold current density for AlGaInP laser diodes with CuPt-type natural superlattice in Ga0.5In0.5P active layer

Abstract

An anisotropy for threshold current densities for AlGaInP laser diodes with CuPt‐type natural superlattice (NSL) in a Ga_0.5In_0.5P active layer, grown on a (001) GaAs substrate, was observed, for the first time. Threshold current densities (J_th) for laser diodes with stripes in the [1̄10] and [110] direction were 1.35 and 2.10 kA/cm², respectively. The lasers with a weak NSL formation in the active layer showed a very small anisotropy in J_th. Stripe direction dependence of electroluminescence (EL) polarization properties were also observed for lasers with well‐developed NSL. The anisotropies in J_th and EL polarization properties are attributed to the existence of the NSL in the active layer and the appearance asymmetry previously observed in the NSL.