9.6Tb/s CP-QPSK Transmission Over 6500 km of NZ-DSF With Commercial Hybrid Amplifiers

Abstract

We experimentally demonstrate, for the first time to the best of our knowledge, an ultralong-haul dense wavelength division multiplexed transmission of $96 \,\, \times \,\, 100$ Gb/s coherent polarization multiplexed quadrature phase-shifted keying transponders over ITU-T G.655 nonzero dispersion-shifted large effective area fibers (NZ-DSF) with an effective core area of 72 $\mu \text{m}^{2}$ , employing both commercial erbium-doped fiber amplifiers (EDFA) and hybrid EDFA + Raman amplification systems. Using the state-of-the-art digital pulse shaping and digital preemphasis algorithms, we report $\sim 1.5$ dB back-to-back optical signal-to-noise ratio penalty at pre forward error correction (FEC) bit error rate (BER) threshold ( $3.8\times 10^{-2}$ ), with respect to theoretical performance. In particular, we demonstrate $\sim 6500$ km transmission across the entire C-band, at pre-FEC BER of $3.8\times 10^{-2}$ , employing EDFA + backward Raman amplification—where the central channel (1552.2nm) had sufficient margin to enable transmission of up to $\sim 8000$ km. Furthermore, we report that hybrid amplification enables up to $\sim 60$ % improvement in maximum transmission reach, compared to EDFA based links. To the best of our knowledge, a record capacity-distance product of $\sim 62.4~\textrm {Pb}/\textrm {s}\cdot \textrm {km}$ is achieved for NZ-DSF—an 11-fold increase, compared with the previous literature.