A vertical cavity surface emitting laser having an InP substrate and a lower
mirror
stack comprised of a plurality of alternating layers of AlPSb and GaPSb over the
InP substrate. An InP spacer is over the lower mirror stack. An active region is
over the InP spacer, and a tunnel junction is over the active region. Then a top
mirror structure comprised of a low-temperature formed first GaAs buffer layer,
a high-temperature formed second GaAs seed layer, an insulating structure having
an opening, and a GaAs/Al(Ga)As mirror stack that is grown by lateral epitaxial overgrowth.
