Coating optical glass fibre with carbon - as protection against moisture, by flame decomposition of carbonaceous gas

摘要

Mfr. of a glass fibre includes protecting the fibre during which the glass preform is heated and a gaseous substance contg. C, thermally decomposable to form C, is injected in the neighbourhood of the zone where the glass is heated, thus provoking deposition of a pyrolytic layer of graphite on the periphery of the fibre. The glass preform is pref. drawn at the same time as the protective step is effected at the place where the glass is heated. The carbon forms a protective layer against attack of the glass by moisture preventing defects leading to rupture from forming.