PRODUCTION OF OPTICAL FIBER AND APPARATUS THEREFOR

摘要

PURPOSE:To obtain optical fibers having little defects and causing slight deterioration in characteristic on exposure to radiation and in hydrogen atmosphere, by drawing a preform into a fiber of a constant wire diameter and heat-treating the fiber before coating with a resin. CONSTITUTION:The heated and softened tip of a preform 1 is drawn into a wire under a constant tension while moving the preform 1 in the direction of a heating and melting furnace 4 by a moving device 3 and formed into a fiber 2 of a constnat wire diameter, which is then introduced into a heat-treating furnace 10 and annealed to remove defects therefrom. The resultant fiber 2 is then introduced into a coating unit 5 and subjected to resin coating. Thereby, the fiber 2 is heat-treated before the resin coating and defects of the optical fiber 2 can be removed without causing deterioration in the synthetic resin. When the temperature on the side of the heating and melting furnace 4 is in creased and the temperature on the outlet side is decreased, the annealing effect can be further improved.