WDM transmission of 603-Gb/s superchannels over 845 km of 7-core fiber with 42.2 b/s/Hz spectral efficiency

We demonstrate 845-km WDM transmission of eight 100-GHz-spaced 603-Gb/s superchannels in each core of a 76.8-km 7-core fiber placed in a recirculating loop. Space- and polarization-division multiplexing of 16-QAM OFDM signals yields a spectral efficiency of 42.2 b/s/Hz.