  Achievable information rates (AIRs) of wideband optical communication systems
using ~40 nm (~5 THz) EDFA and ~100 nm (~12.5 THz) distributed Raman
amplification are estimated based on a first-order perturbation analysis. The
AIRs of each individual channel have been evaluated for DP-64QAM, DP-256QAM,
and DP-1024QAM modulation formats. The impact of full-field nonlinear
compensation (FF-NLC) and probabilistically shaped constellations using a
Maxwell-Boltzmann distribution were studied and compared to electronic
dispersion compensation. It is found that a probabilistically shaped DP-1024QAM
constellation combined with FF-NLC yields AIRs of ~75 Tbit/s for the EDFA
scheme and ~223 Tbit/s for the Raman amplification scheme over 2000 km standard
single mode fibre transmission.
