| 摘要 |
PROBLEM TO BE SOLVED: To provide a dispersion-shifted optical fiber(DSF) capable of reducing a non-linear effect and reducing especially a dispersion slope. SOLUTION: The DSF is constituted so as to have values that a 1st ring part 2 with a refractive index n1 , a 2nd ring part 3 with a refractive index n2 , a 3rd ring part 4 with a refractive index n3 , and a clad pat 5 with a refractive index n4 are successively formed around a center core part 1 with a refractive index n0 , n0 >n4 , n2 >n4 , n3 <n4 , n1 <n4 , and n0 <n2 are set up, wavelength dispersion is almost zero but is not just zero in a 1.55 μm wavelenght band, an effective cross-sectional area is 80 to 130 μm<2> , a bend loss is <10 dB/m, a dispersion slope is <+0.1 ps/km/nm<2> , and single mode propagation is always set up in 1.55 μm band of cut-off wavelength. |
