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Influence of the channel number on the optimal dispersion map due to XPM in WDM links

Costa, N. ; Cartaxo, A.

IEEE/OSA Journal of Lightwave Technology Vol. 26, Nº 22, pp. 3640 - 3649, November, 2008.

ISSN (print): 0733-8724
ISSN (online): 0733-8724

Journal Impact Factor: 2,567 (in 2015)

Digital Object Identifier: 10.1109/JLT.2008.925676

Abstract
The influence of the channel number on the optimal
dispersion map (ODM) due to cross-phase modulation (XPM)
in wavelength division multiplexed links is assessed using an
analytical model. The analytical model is validated by comparison
with numerical simulation using two different methods: the
pump-probe method and a realistic method in which all channels
are digitally modulated carriers. It is shown that there are
usually, at least, two local ODMs due to XPM: one characterized
by negative residual dispersion per span (RDPS) and another
characterized by positive RDPS. These two local ODMs due
to XPM lead to similar XPM-induced degradation. However,
the local ODM with negative RDPS shows always much higher
tolerance to the dispersion map (DM) variation. Furthermore, as
the ODM due to the combined effect of self-phase modulation
and group-velocity dispersion is characterized by negative RDPS
when reduced and moderate power levels are used, the use of the
local ODM due to XPM with negative RDPS is recommended.
This local ODM due to XPM remains approximately the same as
long as, at least, 8 channels are transmitted when 100 or 50 GHz
channel spacings are used and 12 channels are transmitted
when 25 GHz channel spacing is used. However, the high XPM
tolerance to the DMvariation for 25 GHz channel spacing leads to
the conclusion that the ODM for 8 channels is the recommended
DM in case of an arbitrary number of channels, independently
of the channel spacing. These outcomes are independent of the
power level, number and length of spans and transmission fiber
type.