1.6 bit/s/Hz, 6.4 Tbit/s OCDM/WDM (4 OCDM /spl times/ 40 WDM /spl times/ 40 Gbit/s) transmission experiment

We demonstrate the transmission of 6.4 Tbit/s OCDM/WDM (4 OCDM /spl times/ 40 WDM /spl times/ 40 Gbit/s) using, only the C-band wavelength region. A record of 1.6 bit/s/Hz spectrum efficiency is achieved by QPSK optical encoding/decoding along with optical time-gating and optical thresholding in addition to polarization multiplexing.