Fatigue resistant optical fiber
AssigneeAT&T Bell Laboratories
InventorsDarryl L. Brownlow, David J. DiGiovanni, Daryl Inniss
Life of this patent
Estimating the term…
Abstract
A silica-based optical fiber is provided, which has improved resistance to static fatigue. The fiber includes an outer layer of modified, fused silica which contains zirconia and, optionally, alumina.
Claims18
An optical fiber having a core and a cladding surrounding the core, at least a first portion of the cladding comprising silica-based glass, wherein:
- a) the cladding has at least one outer layer which surrounds the first portion;
- b) the outer layer is doped with a dopant composition comprising at least one metal oxide;
- and
- c) the dopant composition is effective for producing, in the resulting fiber, a stress corrosion parameter of 30 or more, without producing, in the resulting fiber, a residual, compressive stress.
A method for manufacturing an optical fiber including the step of drawing fiber from a solid, rod-like preform which comprises at least one outer portion of silica-based glass, the outer portion having an outer surface, the method comprising, before the drawing step, the steps of:
- a) depositing a particulate layer on the outer surface, the particulate layer comprising silica doped with a dopant composition which comprises at least one metal oxide;
- and
- b) sintering the particulate layer to form an outer glass layer on the preform;
- wherein
- c) the dopant composition is effective for producing, in the resulting fiber, a stress corrosion parameter of 30 or more, without producing, in the resulting fiber, a residual, compressive stress.
The method of claim, 11 wherein the zirconia is present in an amount such that the ratio of the number density of zirconium atoms in the outer layer to the number density of silicon atoms, to be referred to as "Zr:Si", is at least about 0.5% and not more than about 8%.
Dependencies are inferred from the claim text.