Tom Gavrielides
Air Force Research
Semiconductor lasers
subject to delayed polarization rotated feedback
We examine several system
configurations in which one or more semiconductor lasers are coupled
through
polarization rotated delayed feedback. We summarize our experimental
and
theoretical results for a single diode laser, steady, periodic and
chaotic
states under the influence of the polarization feedback. The unstable
TM steady
state without feedback now becomes an injection driven state as
theoretical
results agree quite well with the experiments. Additionally, we show
that the
two chaotic lasing polarizations are in a driven synchronization state.
Further,
we summarize the results for unidirectional coupled with rotated
polarization
of two diode lasers and show that synchronous time, perfect
synchronization and
inverse synchronization are obtained. We
also examine the steady states, and periodic states with a particular
emphasis
in square wave pulsations. Experiments and numerical computations are
offered
for stripe lasers as well as for VCSELs. Additional configurations of
the two
coupled face to face system with delayed rotated polarization are
examined and
new results, experimental and theoretical, are outlined. Finally, we
show that
square wave pulsations are robust, span a large feedback region and
coexist
with the steady states of the system.