400 G Transmission of Super-Nyquist-Filtered Signal Based on Single-Carrier 110-GBaud PDM QPSK With 100-GHz Grid

We experimentally demonstrate a coherent transmission system with a high symbol rate using up to 110-GBaud PDM-QPSK signals. Super-Nyquist-filtering technology is used to narrow down the bandwidth of a single channel on a 100-GHz grid. The performance of the high baud rate electronic time division multiplexed-based super-Nyquist-filtered signal is also studied under the aggressive optical filtering elements in multiple reconfigurable optical add-drop multiplexers (ROADMs) nodes during transmission. We successfully transmit 100-GHz-grid, 20 channel single-carrier 440-Gb/s super-Nyquist 9-QAM-like signal over 3600-km ultralarge effective-area fiber (ULAF) at a high net SE of 4 b/s/Hz (after excluding the 7% hard-decision FEC overhead). The highly filtering tolerant performance of the 9-QAM liked super-Nyquist signal is also experimentally demonstrated. Using this scheme, we then successfully transmit ten channel 440-Gb/s signal over 3000-km ULAF and ten cascaded 100-GHz-grid ROADMs based on the 110-GBaud QPSK. Such signal is coherently detected and processed after a real-time oscilloscope at 160-GSa/s sampling rate with 65-GHz bandwidth.