Hermetically coated optical fiber and production of the same.

摘要

A hermetically coated optical fiber comprising a core (1) made of glass, a cladding (2) made of quartz glass surrounding the core the outermost layer (5 or 2) of which glass contains fluorine, and a carbon layer (4) surrounding the fluorine-containing glass layer (5 or 2), which optical fiber has good initial strength and fatigue characteristics.