Modeling and experiments of Raman assisted ultra long-haul terrestrial transmission over 7500 km

We have developed a simulator that accurately predicts OSNR and Q of Raman assisted transmission systems. It was validated in a 16/spl times/12.3 Gbit/s recirculation loop transmission experiment over 7500 km utilizing 90 km spans. We demonstrated Q values with an average margin of 5.7 dB over the FEC limit with 23% overhead.