Raman Amplification Optimization in Short-Reach High Data Rate Coherent Transmission Systems.

We compared the transmission performances of 600 Gbit/s PM-64QAM WDM signals over 75.6 km of single-mode fibre (SMF) using EDFA, discrete Raman, hybrid Raman/EDFA, and first-order or second-order (dual-order) distributed Raman amplifiers. Our numerical simulations and experimental results showed that the simple first-order distributed Raman scheme with backward pumping delivered the best transmission performance among all the schemes, notably better than the expected second-order Raman scheme, which gave a flatter signal power variation along the fibre.

RIN induced penalties in G.654.E and G.652.D based distributed Raman amplifiers for coherent transmission systems.

Relative intensity noise (RIN) induced penalties were experimentally measured in distributed Raman amplifiers (DRAs) for G.654.E and G.

Impact of pump-signal overlap in S+C+L band discrete Raman amplifiers.

We experimentally investigate the impact of pump-signal overlap in ultra-wideband (>13THz) Raman amplifiers and measure the transmission penalty on 30GBaud PM-QPSK signals due to adjacent Raman pumps in a 15dB gain, 150nm (∼18.8THz) S+C+L-band discrete Raman amplifier. We present an efficient numerical model to predict the performance penalty induced by crosstalk from Rayleigh backscattered light from backward-propagating Raman pumps showing good agreement with the experimental results.

High-capacity multi-span transmission performance characterization of broadband discrete Raman amplifier.

The performance of a multi-span transmission link compensated with a >75nm broadband discrete Raman amplifier is experimentally evaluated using multiple DP-x-QAM modulation formats over a multi-channel C + L band WDM grid with up to 182 × 50 GHz spaced channels.

Low transmission penalty dual-stage broadband discrete Raman amplifier.

We present a broadband (>70nm), dual stage, discrete Raman amplifier designed with small and standard core fibres to maximize gain and minimize nonlinearity. The amplifier provides ~19.5dB net gain, 22.

Impact of input FBG reflectivity and forward pump power on RIN transfer in ultralong Raman laser amplifiers.

Relative intensity noise transfer from the pump to the signal in 2nd-order ultra-long Raman laser amplifiers for telecommunications is characterized numerically and experimentally. Our results showcase the need for careful adjustment of the front FBG reflectivity and the relative contribution of forward pump power, and their impact on performance. Finally, our analysis is verified through a 10 × 30 GBaud DP-QPSK transmission experiment, showing a large Q factor penalty associated with the combination of high forward pumping and high reflectivities.