METHOD OF PREPARING OPTICAL FIBER PREFORM

摘要

PROBLEM TO BE SOLVED: To provide a method of preparing an optical fiber preform to prevent the fluctuation of drawing due to the skill of workers or an accident and to draw the optical fiber preform having various fluctuated outside diameter and shape to have a predetermined outer diameter to reduce the occurrence of an outside diameter defect part (edge loss). SOLUTION: A heating position 13a in the starting-up of the drawing is set based on the shape of the original preform 3 which is previously measured using a laser outside shape measuring instrument and the drawing is started up. The distance X between the heating position 13a in the starting-up of the drawing and the original preform shoulder part 12a is made equal to the distance Y between the preform shoulder part 12b in the normal drawing and the heating position 13b in the normal drawing or the heating position is shifted to the original preform side by a distance ranging from zero to D when the outside diameter of the original preform is expressed by D. COPYRIGHT: (C)2004,JPO