METHOD FOR DRAWING A PREFORM AND THE PREFORM DRAWN BY THE METHOD

摘要

A method for drawing a basic material of an optical fiber and the basic material of the optical fiber drawn by the method are provided to draw the basic material to obtain a basic material rod which does not require a process of correcting a bent part from a basic material ingot. According to the method for fabricating a basic material of an optical fiber by drawing a basic material ingot(21) into a basic material rod(22) having a smaller diameter, the basic material ingot is drawn as controlling the position of a neck down(29) to be a target position on a horizontal plane of the basic material ingot. And the direction and the amount of the bending of the drawn basic material rod are measured, and the target position is adjusted on the ground of the result. The position of the neck down is controlled to be the target position by adjusting the position of a swing part of the basic material ingot.