10 $\times$ 224-Gb/s POLMUX-16QAM Transmission Over 656 km of Large-${\rm A}_{\rm eff}$ PSCF With a Spectral Efficiency of 5.6 b/s/Hz

The authors demonstrate the successful transmission of 10 channels with 224-Gb/s POLMUX-16QAM modulation (28 GBaud) on a 37.5-GHz wavelength grid. Using large-A
_eff
pure-silica-core fibers they show a 656-km transmission distance with a spectral efficiency of 5.6 b/s/Hz. They report a back-to-back performance penalty of 3.5 dB compared to theoretical limits at the forward-error correction (FEC) limit (bit-error rate of 3.8·10
^-3
), and a margin of 0.5 dB in Q-factor with respect to the FEC limit after 656 km of transmission.