Title :
On the Impact of Multipath Interference Noise in All-Raman Dispersion-Compensated Links
Author :
Tenenbaum, Stefan ; Poggiolini, Pierluigi
Author_Institution :
Dipt. di Elettronica, Politecnico di Torino
Abstract :
The impact of multipath interference (MPI) in all-Raman multispan dispersion-compensated links operating at 42.67 Gb/s was studied. D+/D- and D+/D-/D+ compensation schemes were considered using different fiber sets. Optical signal-to-noise ratio (OSNR) penalties due to MPI were calculated for several backward-pumped system configurations, imposing system target OSNR levels suitable for intensity modulation with direct detection (IMDD) and differential phase-shift keying (DPSK). The analysis in this paper confirmed that the D+/D-/D+ OSNR penalty is typically much less than that of the D+/D- scheme. The authors then estimated the increase due to MPI in the number of spans required to satisfy a target OSNR for a given total link length, taking into account Kerr nonlinearities. It turned out that such an increase can be very significant (up to 15%-20%) with the D+/D- scheme and lower but nonnegligible (5%-10%) with the D+/D-/D+ schemes. The analysis confirms that, to substantially curtail the span increase, both forward and backward pumping should be adopted, as recent experimental results have shown. Finally, at the lower OSNR levels required by DPSK with respect to IMDD, the impact of MPI was shown to be smaller across all configurations
Keywords :
Raman spectra; differential phase shift keying; intensity modulation; optical fibre communication; optical fibre dispersion; optical noise; optical pumping; 42.67 Gbit/s; Kerr nonlinearities; all-Raman dispersion-compensated links; backward pumping; backward-pumped system; compensation scheme; differential phase-shift keying; direct detection; forward pumping; intensity modulation; multipath interference noise; multispan dispersion-compensated links; optical signal-to-noise ratio penalties; Backscatter; Differential quadrature phase shift keying; Erbium-doped fiber amplifier; Interference; Optical fiber amplifiers; Optical noise; Optical pumping; Semiconductor optical amplifiers; Signal to noise ratio; Stimulated emission; Differential phase-shift keying (DPSK); Raman amplification; double Rayleigh backscatter (DRBS); forward pumping; multipath interference (MPI); ultra-long-haul systems;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2006.883656
