| 摘要 |
An optical fiber according to an embodiment of the present invention is provided with a center core, a side core, and a cladding. The center core includes a ring part where a relative index difference varies discontinuously, in its peripheral region, and when a is a radius from a core center to an outside of the ring part and c is a radius to a position where the relative index difference is maximum in the side core, an index profile is realized in a shape where c/a is in the range of 2.25 to 2.50, so as to enable setting of a dispersion value, a cable cutoff wavelength, a bending loss in the diameter of 20 mm, and an effective area in desired ranges. |
