An effective way of increasing the overall optical fibre capacity is by expanding the bandwidth used to transmit signals. In this paper, the impact of expanding the transmission bandwidth on the optical communication system is experimentally studied using the achievable rates as a performance metric. The trade-offs between the use of larger bandwidths and higher nonlinear interference (NLI) noise is experimentally and theoretically analysed. The growth of NLI noise is investigated for spectral bandwidths from 40 GHz up to 7.3 THz using 64-QAM and Nyquist pulse-shaping. Experimental results are shown to be in line with the predictions from the Gaussian- Noise model showing a logarithmic growth in NLI noise as the signal bandwidth is extended. A reduction of the information rate of only 10% was found between linear and non-linear
transmission across several transmission bandwidths, all the way up to 7.3 THz. Finally, the power transfer between channels due to stimulated Raman scattering effect is analysed showing up to 2 dB power tilt at optimum power for the largest transmitted bandwidth of 7.3 THz.
Copyright: IEEE. This work is licensed under a Creative Commons Attribution 3.0 License. For more information, see http://creativecommons.org/licenses/by/3.0/.
Funding: in part by Becas Chile, in part by UK EPSRC UNLOC Programme under Grant EP/J017582/1, in part by FP7 ITN Programme ICONE(608099), and in part by
the Royal Academy of Engineering under the Research Fellowships scheme.
- GN model, nonlinear effects, optical fibre, optical fibre communications