Real-Time Demonstration of 75 GHz-Spaced DWDM Single-Carrier 400G CFP2-DCO Over 1500 km

Metro and long-haul optical networks drive the need of higher baud rate coherent hot-pluggable modules to achieve a lower total power consumption and flexible operation. In this paper, a pluggable 400G CFP2-DCO module carrying a net data rate of 424.9 Gb/s was demonstrated to achieve a high spectral efficiency of 5.67 bit/s/Hz by using either a pair of 64ch 75 GHz-spaced 3
^th
order super-Gaussian shaped DWDM mux/demux in a point-to-point system, or by ROADMs in a multi-span optical network. With the help of probabilistic constellation shaping, soft-decision forward error correction (SD-FEC), a high bandwidth coherent driver modulator (≥40 GHz) and a high-bandwidth intra-dyne coherent receiver (≥36 GHz), a superior back-to-back OSNR performance of 20.1 dB was achieved. For the point-to-point system, a good OSNR margin was experimentally verified up to 1500 km by considering the laser and mux/demux frequency drifts over lifetime. For the multi-span ROADM network, we investigated the filtering effect due to cascaded ROADMs and found that a tolerable OSNR penalty was observed after passing through 13 stages of ROADM.