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.