PRODUCTION OF OPTICAL FIBER PREFORM

摘要

PURPOSE: To provide a method for producing an optical fiber preform having a well suppressed fluctuation in outside diameter in the longitudinal direction. CONSTITUTION: Glass fine particles produced in a flame of a burner are deposited in the axial direction of a rotating central member 1 to produce a porous optical fiber preform. An excessively long large-diameter part 2' gradually enlarging the diameter from a part of the same outside diameter as that of the central member 1 is formed in at least one end of the central member 1 so that the average rate of change in the outside diameter in the excessively long part 2' may be tanθ<=2.5 when the tilt angle from the end of the central member 1 isθ. Thereby, a region of the fluctuation in the outside diameter is shortened.