APPARATUS FOR THE PRODUCTION OF HERMETICALLY COATED OPTICAL FIBER

摘要

The present invention is directed to an apparatus for the production of a hermetically coated optical fiber in which a glass preform for an optical fiber is melt drawn in a melt drawing furnace to produce a bare optical fiber which is passed to a reactor where a feed gas is supplied. The bare optical fiber is coated with a thin carbon coating made from the feed gas using a chemical vapour deposition (CVD) method wherein the reactor comprises an upper portion to which the feed gas is supplied, a middle portion in which the CVD method is substantially carried out and a lower portion from which an exhaust gas is withdrawn, and a cross sectional area of the middle portion perpendicular to a longitudinal direction of the optical fiber is larger than that of the upper portion.