Anti-Stokes contribution to the SBS Stokes gain in remotely seeded bidirectional NG-PON systems
Vujicic , Z.
Pavlovic, N. P. T.
Optics Express Vol. 25, Nº 14, pp. 16182 - 16195, July, 2017.
ISSN (print): 1094-4087
Scimago Journal Ranking: 1,52 (in 2017)
Digital Object Identifier: 10.1364/OE.25.016182
We assess the importance of Stimulated Brillouin scattering (SBS) anti-Stokes wave on reflection tolerance in remotely seeded wavelength-division multiplexing passive optical networks (WDM PON). Experimental validation of the extended model for the externally seeded SBS is presented towards assessing the conditions in which the anti-Stokes contribution becomes relevant in the variant scenario of remotely carrier-seeded PON. We identify relevant operating conditions in which the latter can no longer be reliably neglected, and analyze the remote seed power budget implications of such contribution. Considering typical launch powers in PON systems we found that, even for seed launch powers below SBS threshold, non-optimized upstream (US) power spectral density may lead to a considerable anti-Stokes contribution to the SBS gain. In effect, in order to maintain a reference optical return loss (ORL) of 32 dB in such scenario, anti-Stokes wave contribution imposed rigorous remote seed power budget restrictions depending on fiber parameters.