| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber suited to an optical transmission line for controlling the dispersion of the whole line to be nearly zero by combining plural optical fibers. SOLUTION: In the optical fiber having graded refractive indexes of a three- layer core type, a ratio refractive difference Δ1 with respect to the clad of its center core is 0.75% to 0.90%, dispersion in a wavelength 1.55 μm is -18 ps/nm/km to -8 ps/nm/km, and an effective core cross-sectional area Aeff in the wavelength 1.55 μm is >=32 μm2. |
