METHOD OF DRAWING OPTICAL FIBERS

摘要

PROBLEM TO BE SOLVED: To provide a high speed method of drawing optical fibers at a high speed wherein fibers are less likely to break during the rise time from the start of drawing the optical fibers until the operation reaches the steady state. SOLUTION: In drawing optical fibers, the outer diameter of the inner clad of the two-layer cladding is made smaller than the target value during the rise time from the start of drawing optical fibers until the operational speed is accelerated to the target rate, or at least when the operational speed approaches the proximity of the target rate. As the operational speed reaches the target rate, the outer diameter of the inner clad is gradually increased to the target value and the steady state operation is continued. As the shear rate of the resin in the second layer die can be maintained low, the fibers are less likely to break.