MULTI-CORE FIBER

摘要

There is provided a multi-core fiber that can suppress the crosstalk between cores adjacent to each other even in the case where the multi-core fiber is nonlinearly disposed while suppressing splicing losses. A multi-core fiber (1) includes an even number of six or more of cores and a clad (20) that surrounds the outer circumferential surfaces of the cores. The cores are formed of two types of cores (11) and (12) in which an effective refractive index difference in a fundamental mode is 0.002 or less in a predetermined range or more that the effective refractive index difference in the fundamental mode is varied according to a core pitch. Two types of the cores (11) and (12) are alternately and annularly disposed at regular spacings. A difference in the mode field diameter of light propagating through the cores (11) and (12) is 1 µm or less.