Transoceanic Transmission of 40 $\,\times\,$117.6 Gb/s PDM-OFDM-16QAM Over Hybrid Large-Core/Ultralow-Loss Fiber

We experimentally demonstrated transmitting 40 × 117.6 Gb/s 16 quadrature amplitude modulation with orthogonal frequency division multiplexing modulation over 10 181 km. The following techniques are applied to achieve error-free transmission: 1) hybrid large-core/ultralow-loss fibers were used for improving received optical signal-to-noise ratio while enhancing fiber nonlinearity tolerance; 2) multiband nonlinearity compensation algorithm was performed to further improve nonlinearity tolerance; 3) the forward error correction (FEC) limit of 5.3 dB provided by the concatenation of hard-decision and soft-decision FEC codes ensures to have error-free transmission after turbo equalizer with memory of three symbols, thus attaining a spectral efficiency of 4.7 b/s/Hz.