Optical fiber including intra-cladding barrier layer

Abstract

A hydrogen diffusion barrier is included as an intra-cladding layer (i.e., a “ring”) within an optical fiber structure. The hydrogen diffusion barrier ring may comprise alumina (or other glass oxides) and is positioned within the fiber cladding at an optimum location with respect to the central core region of the optical fiber. The thickness of the barrier ring may be controlled by fabrication processes to control properties such as hydrogen permeability. Other alkali and alkaline earth metal oxides may be included in the composition of the barrier ring and are useful in preventing crystal formation during the fiber fabrication process.

Dependencies are inferred from the claim text.