Large-effective-area ten-core fiber with cladding diameter of about 200 µm.

A multicore fiber with two-pitch layout is proposed to overcome the trade-off between core number and a cladding diameter of a standard hexagonal layout with a single-core pitch. A fabricated ten-core fiber simultaneously realizes effective area of about 120 µm(2) at 1550 nm, small crosstalk, and cladding diameter of 204 µm. The crosstalk between the center core and outer cores is about 30 dB smaller than that between outer cores. The small crosstalk of the center core would help to keep the transmission quality of the center core at the same level as that of the outer cores.