'Institute of Electrical and Electronics Engineers (IEEE)'
Abstract
We experimentally demonstrated the transmission of 312 × 35 GBd DP-256QAM over 9 × 70 km spans using hybrid distributed Raman-EDFA (HRE) amplifiers with a continuous 91 nm gain bandwidth. A total throughput of 120 Tbit/s over 630 km is demonstrated, with a net achievable information rate after SD-FEC of 10.99 bit/symbol. We further perform an exten- sive, theoretical assessment of the noise contributions originating from amplifier, transceiver sub-system and fiber nonlinearity using the Gaussian noise model in the presence of inter-channel stimulated Raman scattering (ISRS GN model). The ISRS GN model accounts for arbitrary, wavelength dependent signal power profiles along fiber spans, which is vital for the modeling of ultra- wideband transmission, particularly for hybrid Raman-amplified links. It is found that, due to the low noise HRE amplifier and a transmission distance of 630 km, the noise originating from the transceiver sub-system imposed a penalty of 5 dB in SNR. The transceiver noise is, therefore, the major performance bottleneck and the main limitation of the system throughput
