摘要 |
Resonances in cross-phase-modulation (CPM) impairment occur in wavelength-division-multiplexed (WDM) transmission systems, having multiple equal dispersion-length amplifier spans, when channels have an integral number of bit walk-throughs per amplifier span. The CPM resonances are reduced by mis-matching the amplifier span lengths (and/or dispersion in each span) so an integral number of bit walk-throughs do not occur in successive amplifier spans. The CPM resonances are reduced by adding different lengths of dispersion-compensating fiber to each span, using different modulation bit rates and/or clock phase delay for each channel, and using different wavelength-selective clock phase delays for each channel.
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