Single-Channel 7.68 Tbit/s, 64 QAM Coherent Nyquist Pulse Transmission over 150 km with a Spectral Efficiency of 9.7 bit/s/Hz

We report a 640 Gbaud, 64 QAM coherent Nyquist pulse transmission over 150 km with mode-locked lasers. A record capacity of 7.68 Tbit/s in a single-channel transmission was achieved with a 9.7 bit/s/Hz spectral efficiency.