Patent ID: 11256026

Abstract:
An MCF cable according to an embodiment contains a plurality of MCFs each including at least one coupled core group and a common cladding. Λ is set such that κ at a wavelength of 1550 nm is falls within a range of from 1×10−1 [m−1] to 1×103 [m−1], and (βΛCavg)/(2κ) or (βΛCf)/(2κ) is set in a specific range in a wavelength band of from 1530 nm to 1625 nm, where Cavg [m−1], Cf [m−1], and ftwist [turn/m] represent the average curvature, the pseudo-curvature, and the average torsion, respectively, for each MCF, and κ [m−1], β [m−1], and Λ [m] represent the coefficient of mode coupling between adjacent cores, the average of propagation constants, and the core center-to-center distance, respectively.