January 15, 2020

74.38 Tb/s Transmission over 6300 km Single Mode Fibre Enabled by C+L Amplification and Geometrically Shaped PDM-64QAM

  • Barnes S.
  • Bayvel P.
  • Edwards A.
  • Galdino L.
  • Ionescu M.
  • Killey R.
  • Lavery D.
  • Pelouch W.
  • Semrau D.
  • Sillekens E.

© 1983-2012 IEEE. Ultrawide-bandwidth optical amplification over almost 90 nm, covering the C+L bands, is described. Complemented by system-tailored geometrical constellation shaping and nonlinearity compensation, it enabled a record capacity transmission of 74.38 Tb/s over 6,300 km of G.654 single-mode fibre. The hybrid scheme, combining backward Raman pre-amplification with EDFA, significantly improves the average effective noise figure across the entire bandwidth, allowing the use of span lengths of 70 km. The system-tailored GS-64QAM constellation was optimised to both linear link impairments and transceiver nonlinearities, improving the gap to the AWGN channel capacity relative to square 64QAM from 0.6 bit/symbol to 0.35 bit/symbol. We experimentally evaluated the system performance using the bit-wise achievable information rate (AIR) and signal-to-noise ratio (SNR) at the end of transmission, as well as post SD-FEC BER.

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