| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of manufacturing an optical fiber having both low Rayleigh scattering loss and low OH absorption loss at low cost.SOLUTION: In a step of producing an optical fiber preform 2, the optical fiber preform 2 in which a power ratio of transmission light having the wavelength of 1.38 μm in a core-rod corresponding region of an optical fiber after wire drawing is 99.99975% or more is produced by adding a jacket layer having an average OH concentration of 10 wtppm or more around a core rod having an average OH concentration of less than 1 wtppb, and an OH concentration of 10 wtppm in a region having the thickness of 0.03 μm from the surface of the optical fiber 3 after the wire drawing. In a heating step, a temperature of the optical fiber 3 when entering the optical fiber 3 into a heating furnace 21 is 1400°C or more, a heating temperature of the optical fiber 3 in the heating furnace 21 is 2000°C or less, and a residence time of the optical fiber 3 in the heating furnace 21 is 0.005-1 second. |
