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US 4,734,117 AGranted
Optical waveguide manufacture
AssigneeNorthern Telecom Limited
InventorsPeter J. Pilon, Richard S. Lowe
Life of this patent
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Abstract
Optical waveguide having a fused silica core and a fluorine doped fused silica cladding is made by depositing particulate core silica onto a support tube and then drying and densifying the silica. Further particulate cladding silica is deposited and is heated in a fluorine containing gas to effect drying, fluorine diffusion into and sintering the cladding silica. The support tube is etched away and the resulting tubular preform is heated to collapse it into a rod from which waveguide is drawn, the waveguide having a fluorine doped silica cladding.
Claims6
A method of manufacturing optical waveguides comprising:
- depositing a layer of particulate silica on an outer surface of a fused silica cylindrical support tube having a central bore;
- drying the deposited silica;
- consolidating the dried, deposited silica;
- depositing another layer of particulate silica on the dried consolidated silica to form a preform having a porous outer layer;
- placing said preform having a porous outer layer within a second fused silica tube, and drying and fluorine doping said preform having a porous outer layer by passing a fluorine-containing gas through said second fused silica tube and around said preform having a porous outer layer to form a preform having a doped porous outer layer;
- consolidating said preform having a doped porous outer layer to form a preform having a doped outer layer and heating said second fused silica tube to collapse it onto said preform having a doped outer layer;
- etching away the fused silica cylindrical support tube by passing a mixture of hexafluoride and helium through the central bore, resulting in a tubular preform composite;
- collapsing said composite tubular preform into a rod preform;
- and
- heating said rod preform to a drawing temperature and drawing it into an optical waveguide, said waveguide having a core and a cladding derived from deposited silica, with the cladding being doped with fluorine.
7 more elements
Dependencies are inferred from the claim text.