Patent ID: 7415182

Claim:
An optical fiber cable comprising: first, second and third optical fibers connected together so that signal light traveling through the cable travels through the first optical fiber, then through the second optical fiber and then through the third optical fiber, wherein the second optical fiber has a negative dispersion value, the first and third optical fibers each have a positive dispersion value, the cable optically connects together two optical repeater stations, or an optical repeater station and an end station, pump light is provided to the first, second and third optical fibers by inputting the pump light from an input side of the first optical fiber and an output side of the third optical fiber, so that the pump light is not provided directly to the second optical fiber and is instead provided to the second optical fiber by passing through the first optical fiber or the third optical fiber, to cause Raman amplification to occur in the first, second and third optical fibers, the first and third optical fibers each have an effective area from 55 square microns to 120 square microns and the second optical fiber has an effective area from 15 square microns to 45 square microns, and lengths of the first, second and third fibers are set, and the pump light is provided at a level, so that power level at the input side of the first optical fiber of the signal light traveling through the cable is substantially equal to power level of the signal light at the output side of the third optical fiber.