| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an optical fiber by which the application to mass production of an optical fiber wire having the surface coated with a resin can be made when reducing the Rayleigh scattering intensity and producing the optical fiber having a low transmission loss. SOLUTION: This apparatus for producing an optical fiber comprises a wire drawing device 1 having a wire drawing furnace 11, a heating furnace 21 for annealing and a resin curing part 31. The optical fiber 3 subjected to thermal wire drawing in the wire drawing furnace 11 is fed to the heating furnace 21 for the annealing and a prescribed site of the optical fiber 3 is annealed at a prescribed cooling rate. The annealing in the heating furnace 21 for the annealing is carried out by cooling the optical fiber 3 at <=1,000 deg.C/s cooling rate in a section to provide >=50 deg.C temperature difference of the optical fiber 3 in a part where the temperature reaches 1,300-1,700 deg.C in the optical fiber 3 subjected to the thermal wire drawing. The resultant optical fiber 3 is then coated with a UV resin liquid 52 with a coating die 51 to hot cure the UV resin in the resin curing part 31. Thereby, an optical fiber wire 4 is obtained. |
