Iqbal M A, Tan M, Krzczanowicz L, El-Taher A E, Forysiak W, Ania-Castañón J D, Harper P
Opt Express. 2017 Oct 30;25(22):27533-27542. doi: 10.1364/OE.25.027533.
We demonstrate a low noise bidirectional broadband distributed Raman pumping scheme combining dual order co-propagated pumps without increasing the signal RIN level. The noise performance improvement is compared experimentally and numerically with conventional counter-pumping only and bidirectional pumping with only a 2nd order co-pump for a 70nm bandwidth and 61.5km distributed Raman amplifier. The proposed broadband pumping scheme shows 1.2dB maximum noise figure improvement and extends the long-haul transmission reach up to 6150km with a Q-factor improvement of ~0.7dB compared with counter-pumping only scheme.
