ULTRAVIOLET IRRADIATION REACTOR FOR OPTICAL FIBER AND METHOD FOR MANUFACTURING OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation reactor that suppresses oxygen concentration at a low level to satisfactorily cure an ultraviolet curable resin coated on an optical fiber, and to provide a method for manufacturing an optical fiber.SOLUTION: An ultraviolet irradiation reactor 4 for an optical fiber comprises: a cylindrical quartz tube 42 coated with an ultraviolet curable resin on its outer periphery; an inert gas supply port 48 supplying an inert gas G1 to an upstream-side end part of the quartz tube 42; and an ultraviolet irradiation part 43 irradiating ultraviolet rays from radially outside of the quartz tube 42 to an optical fiber 13 passing through the inside of the quarts tube 42. A cylindrical member 57 having an inner diameter smaller than that of the quartz tube 42 is provided above the quartz tube 42, and the inside of the cylindrical member 57 is filled with an inert gas G2 to allow the optical fiber 13 to be sealed. The cylindrical member 57 has an inner diameter of 2-8 mm and a length of 20-100 mm.SELECTED DRAWING: Figure 2