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.

GSMBE growth and characterizations of AlInP/InGaAsP strain-compensated multiple-layer heterostructures

“…However, the bonding technology is not easily compatible with full-wafer processing and testing capabilities, which constitute the major advantages of the VCSEL geometry for industrial fabrication [4]. The dielectric mirrors cannot be electrically conductive and inhibit homogeneous current injection into the active region [5]. The drawback of InP/air-gap DBRs is a complicated fabrication process and of low thermal conductivity [6].…”

Long-wavelength VCSELs with AlGaAsSb DBRs

“…The basic concept of 1 .55 jtm VCSELs reviewed in this paper is to employ Sb-based lattice-matched DBRs [4], [5].…”

“…There have been two kinds of structures reported so far. One has relatively low-reflective DBRs based on InAlGaAs materials and multiple active regions for high gain which compensate large mirror loss [2].Another one has a single active region and employs A1GaAsSb-based DBRs for high reflectivity [3], [4].…”

A comparative study of AlGaAsSb/AlAsSb distributed Bragg mirrors on InP

“…More recent studies have also described the VCSELs processing and test based on the Bragg mirrors [8,[20][21][22]. However, these studies dealt with Bragg mirrors with an abrupt interface between the ternary and quaternary alloy.…”

“…Several III-V semiconductor materials which satisfy some of the DBRs manufacturing conditions have been experimented on InP substrates. Material systems such as InGaAsP/InP [5,6], AlGaInAs/AlInAs [7,8] and AlGaAsSb/AlAsSb [9][10][11][12][13] have been used in light-emitting devices. Among these systems, the antimonide alloys exhibit the highest refractive index contrast [14,15].…”