High-Capacity Space-Division-Multiplexed DWDM Transmissions Using Multicore Fiber

We describe a new multicore fiber (MCF) having seven single-mode cores arranged in a hexagonal array, exhibiting low crosstalk among them and low loss across the C- and L-band. In order to spatially multiplex and demultiplex optical signals in and out of the MCF, we designed and fabricated a tapered MCF connector (TMC) with ultralow crosstalk and loss for space-division-multiplexing (SDM) transmission. The key crosstalk properties of MCF, including wavelength and distance dependence crosstalk characteristics, and statistical distribution of crosstalk over time, are measured and discussed. Using the MCF and TMC, we experimentally demonstrate a record transmission capacity of 112 Tb/s over a 76.8 km MCF using SDM and dense wavelength division multiplexing. Each core of the MCF carries 160 107 Gb/s polarization-division multiplexed quadrature phase-shift keying (PDM-QPSK) channels on a 50 GHz grid in the C- and L-band, resulting in an aggregate spectral efficiency of 14 b/s/Hz. The system impact of the intercore crosstalk on a 107 Gb/s PDM-QPSK signal is further investigated by transmitting it through the center core while the six outer cores carry same-wavelength 107 Gb/s signals. The system implication of the core-to-core crosstalk on ultralong-haul transmission is also discussed.