Experimental comparison of all-Raman vs. Raman/EDFA hybrid amplification with 40 Gb/s-based ETDM/DWDM transmissions over 400 km TW-RS fibre

Summary form only given. A 400 km TW-RS fibre system with 16 channels of 40 Gbit/s CS-RZ ETDM signals has been used to experimentally compare the relative merits of all Raman and Raman/EDFA hybrid amplification. In the cases of counter-pumped 10 × 40 km and 5 × 80 km spans, all Raman distributed amplification has allowed best transmission performance, compared to Raman/EDFA hybrid amplification. All Raman transmission yielded up to 1.3 dB system Q improvement in the 40 and 80 km span length systems, compared to systems without Raman gain. The MPI impairment associated with the double Rayleigh scattering effect in all-Raman counter-pumped long span systems, was significantly reduced in an experimental demonstration over 1 × 160 + 2 × 120 km TW-RS fibre, by employing multi-span bidirectionally pumped all Raman amplification.