Coated optical fiber and its manufacturing method

摘要

A coated optical fiber comprising a glass fiber constituted by a silica based glass core and cladding; and a primary coating and a secondary coating which are formed by photo-curing a primary coating resin layer and a secondary coating resin layer which are applied to an outer periphery of the glass fiber, wherein a maximum value As(max) of absorbances As of the secondary coating resin layer before curing with respect to light in a wavelength region of 310 to 340 nm is not more than 0.5, whereas absorbances Ap of the primary coating resin layer before curing with respect to light in this wavelength region are greater than the absorbances As.