12-core fiber with one ring structure for extremely large capacity transmission.

The feature of a multicore fiber with one-ring structure is theoretically analyzed and experimentally demonstrated. The one-ring structure overcomes the issues of the hexagonal close-pack structure. The possibility of 10-core fiber with Aeff of 110 µm(2) and 12-core fiber with Aeff of 80 µm(2) is theoretically presented. The fabricated 12-core fibers based on the simulation results realized Aeff of 80 µm(2) and crosstalk less than -40 dB at 1550 nm after 100-km propagation. The MCF with the number of core larger than seven and the small crosstalk was demonstrated for the first time.