| 摘要 |
PROBLEM TO BE SOLVED: To provide a dispersion-shifted optical fiber having a low loss, low dispersion slope and 1.55 micron region. SOLUTION: The core region (a) is one with GeO<SB>2</SB>added in a high concentration. The core region (b) is composed of pure SiO<SB>2</SB>glass. The clad part 3 is arranged in the periphery of the core regions. The clad part 3 is formed with a large number of air holes 4 extending in the longitudinal direction of the optical fiber. The position of the air holes 4 in the clad part 3 is not in disorder but forms a honeycomb shape with a hexagon having a side lengthΛas the basic grid. In the center of the core regions 1, 2, there is a region 3 with a refractive index higher than in the periphery of the core regions 1, 2. The refractive index distribution of the core regions 1, 2 is such that the group velocity dispersion in the operating wavelength of this region 3 becomes a normal dispersion. COPYRIGHT: (C)2004,JPO |
