Low-threshold-current and single-mode surface-emitting laser buried in amorphous GaAs

Abstract

We propose a vertical-cavity surface-emitting laser buried in low-temperature-grown amorphous GaAs (a-GaAs), which was found to be effective for surface passivation of an etched cavity and suppression of high-order transverse modes. The deposition of highly resistive a-GaAs layer on an InGaAs/GaAs active region and AlAs/GaAs mirror layers yielded a significant improvement in threshold current density and differential quantum efficiency. The maximum currents maintaining a stable fundamental transverse mode were also increased by the antiguide effect of a-GaAs with a high refractive index. For a 10-mu m-diameter device, we attained a stable single-mode emission with a threshold current of 0.7 mA.