PRODUCTION OF COATED OPTICAL FIBER

摘要

PURPOSE: To provide a process for producing a coated optical fiber capable of stably forming a coating of a prescribed thickness even if the optical fiber is subjected to drawing at a high speed. CONSTITUTION: This process includes a stage for obtaining the optical fiber 12 by melt spinning a preform for the optical fiber, a stage for cooling the optical fiber 12, a stage for supplying a resin 13 to the outer side of this optical fiber 12 and a stage for applying the coating on the optical fiber 12 by curing this resin 13. A high-temp. layer 14 formed on the outer side of the optical fiber 12 and a low-temp. layer 15 formed on the outer side of this high-temp. layer 14 are adjusted as to satisfy (μr /μh )/ΔT}×100<=13 (μr is the viscosity of the low-temp. layer 15,μh is the average viscosity of the high-temp. layer 14,ΔT is the difference between the average temp. of the high-temp. layer 14 and the temp. of the low-temp. layer 15) at the time of supplying the resin 13 to the outer side of the optical fiber 12.