PURPOSE: To strip common coating layers and to separate the coated fibers to single fibers without damaging the internal coated fibers.
CONSTITUTION: This method for separating a multiple coated optical fiber from ribbon 1 formed by arranging the plural internal coated fibers consisting of optical fibers coated with coating layers to a plane form and integrally coating these coated fibers with the common coating layers 11, 13 has a stage for applying a temp. gradient to the optical fiber ribbon 1 and curving stages for curving the optical fiber ribbon at the curvature having the center of the radii of curvature on the high-temp. side of such temp. gradient. The bending radii of the first and second curving stages are R respectively satisfying R<RB when the breaking elongation of the material forming the common coating layers at the temp. T of the temp. of the common coating layers 11 on the low-temp. side of the temp. gradient is defined as p, the coefft. of thermal expansion of the material formed with the common coating layer as α, the temp. difference between the high-temp. side temp. and low-temp. T side of the temp. gradient as ΔT and the thickness of the multiple coated optical fiber ribbon 1 as t and when the bending radius satisfying equation (RB+t/2)/RB=1+p-αμ≥T/2 is defined as RB.
TSUNODA TATSUYA
OGAWA NAOSHI
NIPPON TELEGRAPH & TELEPHONE