US Patent 7099541 Optical fiber cable

An optical fiber cable including a plurality of optical fibers, each optical fiber having a characteristic value in a middle field which is larger than characteristic values in fields other than the middle field of the optical fiber. The characteristic value in a respective field is a nonlinear refractive index of the optical fiber in the field divided by an effective cross section of the optical fiber in the field. The middle field and the characteristic value in the middle field are set as a combination to suppress a nonlinear phase shift generated in light transmitted through the plurality of optical fibers.