Amorphous GaAs passivation of ion-beam-etched InGaAs vertical-cavity surface-emitting lasers

Abstract

We report the successful application of a low-temperature-grown amorphous GaAs (a-GaAs) layer for surface passivation of InGaAs vertical-cavity surface-emitting lasers. The deposition of an a-GaAs layer on ion-beam-etched laser posts showed a significant improvement, more than 20%, in the threshold current density and the differential quantum efficiency. We also observed an increase in the maximum currents maintaining a stable fundamental transverse mode for 15-mu m- and 20-mu m-diameter devices which was the antiguide effect of the a-GaAs layer with high refractive index.