Molecular beam epitaxial growth of monolithic 1.55 μm vertical cavity surface emitting lasers with AlGaAsSb/AlAsSb Bragg mirrors

Abstract

The molecular beam epitaxy and the characterization of single-step grown long wavelength vertical cavity surface emitting lasers (LW–VCSEL) are reported. The devices were fabricated using highly reflective AlGaAsSb/AlAsSb distributed Bragg reflectors (DBRs), and an AlGaInAs-based active region embedding a tunnel (or Esaki) junction. The VCSELs operate at 1.55 μm at room temperature with a threshold current density of 1.4 kA/cm2. Characterization of the VCSELs and DBRs’ thermal and electrical properties is presented. Major improvement on the voltage drop in an InGaAs capped DBR is demonstrated, resulting in a value as low as 40 mV/pair.