708-km combined WDM/SDM transmission over few-mode fiber supporting 12 spatial and polarization modes

We transmit 16 WDM channels using 20-Gbd QPSK over 12 spatial and polarization modes of 708-km few-mode fiber at a spectral-efficiency-distance product of 11328 km bit/s/Hz.The transmitted signals are recovered using off-line 12 ×12 multiple-input multiple-output digital signal processing.