OPTICAL FIBER PRODUCTION AND OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide a process for producing an optical fiber capable of easily producing an optical fiber of a specified outside diameter adjusted in characteristics with respect to an optical axis direction and the optical fiber. SOLUTION: A first clad material 12 having a refractive index smaller than the refractive index of a core material 11 is formed around the core material 11 of the specified diameter by an intermediate production stage, by which an intermediate is produced. The intermediate is adjusted in the outside diameter of its first clad material 12 with respect to the optical axis direction by an outside diameter adjustment stage. The intermediate is stretched by a stretching stage, by which the outside diameter thereof is kept constant. A second clad material 13 having the refractive index smaller than the refractive index of the core material 11 is formed around the intermediate in a preform production stage, by which the transparent vitrified preform is produced. The preform is drawn by a drawing stage, by which the optical fiber having the specified diameter is produced.