FLAME POLISHING METHOD FOR OPTICAL FIBER REFORM

摘要

PROBLEM TO BE SOLVED: To provide a flame polishing method which is capable of eliminating the nonuniformity by the flaws and impurity foreign matter on an optical fiber preform surface, the residual strain in the optical fiber preform and the cloud by the glass particulates adhered to the preform surface and producing the smooth optical fiber preform. SOLUTION: The flame polishing method for the optical fiber preform is a flame polishing method for the preform 1 which melts the flank of the axially rotating optical fiber preform 1 by a relatively moving flame 14 and removes the nonuniformity of the preform 1 by a first flame polishing stage of melting the entire surface of the flank while regulating the axial rotating speed of the preform 1 in accordance with the molten area S of the preform 1 and the relative moving speed V of the flame 14, then eliminates the cloud of the surface and internal strain of the preform 1 by a second flame polishing stage for melting the preform 1 at the temperature lower than the temperature of the first flame polishing stage.