| 摘要 |
PROBLEM TO BE SOLVED: To restrain distortion resulting from nonlinear phenomena and wavelength dispersion, reduce bending losses, and ensure single-mode operation. SOLUTION: When a center core 1, a first side core 2, a second side core 3, and a third side core 4 differ from a silica level respectively by Δ1, Δ2, Δ3, Δ4, then 0.6% <=Δ1<=0.75%, -0.15%<=Δ2<=0, 0.3%<=Δ3<=0.6%, and -0.2%<=Δ4<=-0.05%. The center core 1 has a profile with a refractive index to the power of α (α=1.5-2.5). The absolute value of dispersion at a wavelength of 1.55 μm is 0.5 to 3, and a dispersion slope in a wavelength band of 1.55 μm is 0.12 ps/nm2/km or less. An effective core cross-sectional area in the same wavelength band is 70 μm2 or more and a bending loss at a bending diameter of 20 mm in the same wavelength bend is 20 dB/m or loss, with a cutoff frequency of 1700 nm or less. |
