Optical fiber wave-guides for signal transmission comprising multiple component glass with an adjusted expansion co-efficient between the core and mantle

摘要

The present invention discloses an optical fiber wave-guide for signal transmission in which the signal fiber has a linear thermal expansion co- efficient in all of the fiber elements above 15×10. sup.-7 /° C. in which the outer mantle is composed of the silicon dioxide modified glass, and the optical fiber wave-guide is composed of an inner silicon dioxide-free mantle employing germanium oxide and other components and has an inner silicon dioxide-free core which is composed of germanium oxide and optionally other additives. The fiber is produced according to the chemical vapor deposition process, and preferably has a refractive index gradient which has the shape of a parabola.