method of manufacturing an optical fiber for ultraviolet irradiation reactor and optical fiber

摘要

PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation furnace for optical fiber for more reducing oxygen concentration in a quartz tube, and for suppressing cloudiness in the quartz tube by smoothly discharging volatile components staying in the quartz tube to the outside and a method of manufacturing an optical fiber.SOLUTION: An ultraviolet irradiation furnace 10 for optical fiber includes: a cylindrical quartz tube 13 through which an optical fiber 11 to whose outer periphery ultraviolet curing resin is applied is made to pass; an inert gas supply port 19 which supplies inert gas G to the upstream end of the quartz tube 13; and an ultraviolet lamp 14 which cures the ultraviolet curing resin applied to the optical fiber 11 by irradiating the outside of the quartz tube 13 with ultraviolet rays of light. Additionally, the ultraviolet irradiation furnace 10 for optical fiber is configured such that the inlet side opening diameter D1 of an inlet 17 at an upper end ranges from 3 to 10 mm, and that the outlet side opening diameter D2 of an outlet 18 at a lower end ranges from 4 to 20 mm, and that the inlet side opening diameter D1 and the outlet side opening diameter D2 are appropriately set so that the outlet side opening diameter D2 can be made larger than the inlet side opening diameter D1.