A. Bononi et al., IMPULSE-RESPONSE OF CROSS-PHASE MODULATION FILTERS IN MULTISPAN TRANSMISSION-SYSTEMS WITH DISPERSION COMPENSATION, Optical fiber technology (Print), 4(4), 1998, pp. 371-383
As shown by Chiang et al. (1996), cross-phase modulation on each chann
el of a wavelength-division-multiplexed transmission system can be vie
wed as a phase modulation, where the modulating signal is the sum of t
he input intensities of all the other copropagating channels, each fil
tered by a low-pass filter, whose bandwidth decreases with the walk-of
f parameter. We give an explicit expression of the impulse response of
such filter in the general case of dispersion mapped transmission sys
tems. We show by simulation that this filter, in intensity-modulated t
ransmission systems, gives an optimal prediction of the signal phase e
ven when the underlying assumption of negligible envelope distortion u
pon which its derivation is based is strongly violated. As an applicat
ion, we show an analytical evaluation of the spectral broadening induc
ed by XPM in multi-span compensated systems. (C) 1998 Academic Press.