Folded Cavity Lasers
In some materials
systems, it has so far been very difficult to
fabricate
vertical cavity lasers with sufficient emission power and efficiency for
most applications. One of these
areas is the 1500-1650nm telecommunications
wavelength range. To solve t
his problem, we have developed methods for
converting more conventional in-plane lasers into surface emitting
devices by introducing folded cavity and external cavity mirrors through
fabrication. This approach brings with it the additional benefit of
avoiding the thinning and cleaving step typically necessary for the
fabrication of stripe lasers. Light within an in-plane laser can
be deflected towards the surface by using microfabricated reflectors. We
have demonstrated folded cavity lasers
along with other microfabricated laser
cavities in the paper entitled “1.57
micron InGaA
s/InP surface emitting lasers by angled focus ion-beam
etching”. The major opportunity
of
these lasers is that standard in-plane
edge-emitting lasers can be converted into
surface emitting lasers with
excellent power and threshold performance. Our work in developing lasers
that do not rely on cleaved facets will ultimately improve the yield of
lasers and enable their on-chip testing, eliminating one of the most
costly steps in current laser fabrication.
