Multiply coated metallic clad fiber optical waveguide

Abstract

There is disclosed a metallic clad glass fiber optical waveguide suitable for use as a high-strength optical transmission line, e.g., for high capacity communications systems and for sensors operating at high temperature. At least two metallic claddings or coatings are formed on the glass waveguide structure, which comprises a core and glass cladding, by coating the glass fiber with at least one of the metallic coatings as it emerges from the furnace with a metal or alloy. The first metal or alloy employed is one that is substantially chemically inert with respect to the material comprising the glass fiber at the deposition temperature during coating of the metal or alloy onto the glass fiber. The second metallic coating may be of the same composition as the first, in order to repair pinholes or to increase the thickness. Alternatively, the second metallic coating may be of a different composition than the first in order to provide the waveguide with mechanical properties that are different than either layer alone could provide. Specific electrical and magnetic properties may also be provided. The metallic coatings prevent chemical or mechanical damage to the glass surface. A plastic coating is optionally provided for additional protection of the metallic surface.