Coherent Optical OFDM Transmission Up to 1 Tb/s per Channel

Coherent optical frequency-division multiplexing (CO-OFDM) is one of the promising pathways toward future ultrahigh capacity transparent optical networks. In this paper, numerical simulation is carried out to investigate the feasibility of 1 Tb/s per channel CO-OFDM transmission. We find that, for 1 Tb/s CO-OFDM signal, the performance difference between single channel and wavelength division multiplexing (WDM) transmission is small. The maximum Q is 13.8 and 13.2 dB respectively for single channel and WDM transmission. We also investigate the CO-OFDM performance on the upgrade of 10-Gb/s to 100-Gb/s based DWDM systems with 50-GHz channel spacing to 100-Gb/s systems. It is shown that due to the high spectral efficiency and resilience to dispersion, for 100-Gb/s CO-OFDM signals, only 1.3 dB Q penalty is observed for 10 GHz laser frequency detuning. A comparison of CO-OFDM system performance under different data rate of 10.7 Gb/s, 42.8 Gb/s, 107 Gb/s and 1.07 Tb/s with and without the impact of dispersion compensation fiber is also presented. We find that the optimum fiber launch power increases almost linearly with the increase of data rate. 7 dB optimum launch power difference is observed between 107 Gb/s and 1.07 Tb/s CO-OFDM systems.