| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a four-core single mode optical fiber and an optical cable capable of improving crosstalk characteristics between adjacent cores while suppressing increase of the number of holes in an optical fiber cross section and refractive index distribution of the cores to be formed in multilayer. <P>SOLUTION: By arranging four core parts 2 in a square lattice shape or in a linear shape within a cross section of a clad part 1, and arranging a low refractive index area 3 having a cross section area for which reduction of the effective cross section of the respective core parts 2 is below 1% and a refractive index smaller than the refractive index of the clad part 1 at the center between the respective adjacent core parts 2 within the cross section of the clad part 1, the crosstalk characteristics between the adjacent cores are reduced to be 50%-10% or less without increase of the number of holes in an optical fiber cross section and refractive index distribution of the core parts to be formed in multilayer. <P>COPYRIGHT: (C)2013,JPO&INPIT |
