Experimental investigation of polarization effects in semiconductor optical amplifiers and implications for all-optical switching
Philippe, Severine, Bradley, Ann LouiseORCID: 0000-0002-9399-8628, Kennedy, Brendan F.ORCID: 0000-0003-4782-0498 and Landais, PascalORCID: 0000-0002-4807-0695
(2008)
Experimental investigation of polarization effects in semiconductor optical amplifiers and implications for all-optical switching.
Journal of Lightwave Technology, 26
(16).
pp. 2977-2985.
ISSN 0733-8724
A free-space contra-propagation configuration is
implemented and pump-probe studies are undertaken in order
to study polarization-dependent gain dynamics in bulk semiconductor optical amplifiers (SOAs) and their application to gain
and polarization switching. The polarization dependence of the
gain compression shows that the co-polarized case, in which
the pump and probe are TE-polarized, is the optimum for gain
switching. When injecting light polarized at 45 , an additional
contribution due to the presence of rotating fields is observed, and
the cross-polarized case is found to be the most promising for polarization switching. The potential for all-optical switching based
on nonlinear polarization rotation (NLPR) induced in the SOA
is then assessed through characterization of the dynamics of the
state of polarization. It is demonstrated that by careful selection
of the orientation of a linear polarizer in front of the detector,
it is possible to reduce the recovery time from 100 to 5 ps. The
improvement comes about from the selection of the intraband fast
gain recovery dynamics. Polarization switching offers potentially
faster switching times compared to gain switching as well as an
extinction ratio improvement of 10 dB.