Patent ID: 9541704
Date: 2017-01-10
CPC Classifications: G02B

Claim:
1. A multi-core optical fiber comprising: a plurality of cores each extending along a central axis and comprised of silica-based glass; a common cladding covering each of the plurality of cores and comprised of silica glass; and a coating provided on an outer peripheral surface of the common cladding and comprised of a material different from silica glass, wherein in a cross section of the multi-core optical fiber perpendicular to the central axis, the plurality of cores are arranged in an equilateral-triangular lattice pattern and a neighboring core pitch Λ [μm] being a distance between centers of neighboring cores is constant, wherein a cable cutoff wavelength λ wherein when a theoretical cutoff wavelength is represented by λ wherein an outer diameter 2r wherein when the multi-core optical fiber is bent in a radius of curvature R in the range of 0.3 m to 3 m over the entire length thereof, both of a neighboring intercore power coupling coefficient and a neighboring identical intercore power coupling coefficient are not more than 2.3×10 wherein when OCT represents a shortest distance from a center of a core located at an outermost periphery out of the plurality of cores, to an outer peripheral surface of the common cladding, OCT wherein when permissible minimum OCT is represented by OCT wherein with a definition of a parameter represented by a formula of Λ(r