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US 4,090,055 AGranted
Apparatus for manufacturing an optical fibre with plasma activated deposition in a tube
AssigneeNorthern Telecom Limited
InventorFrederick David King
Life of this patent
Estimating the term…
Abstract
An optical fibre is manufactured by forming a layer of fused silica, which may or may not be doped, on the inner wall of a fused silica tube by producing a plasma in the reactant gases flowing through the tube. By this means a higher temperature can be maintained inside the tube than at the tubes outer wall. The plasma is produced at substantially atmospheric pressure. Cooling gas is passed along the outer wall of the tube.
Claims4
Apparatus for manufacturing an optical fibre having fused silica layers, comprising:
- a microwave cavity and means for applying a microwave field to said cavity;
- support means for supporting a fused silica tube in said cavity and means for traversing said tube axially in said cavity;
- means for supplying a mixture of gases to a fused silica tube supported in said support means for passage of said mixture of gases through said tube, said mixture of gases comprising a carrier gas, oxygen and a reactant gas comprising a gaseous form of the material to form said fused layers;
- and
- means for supplying a cooling medium for passage along the outside of a fused silica tube supported in said support means;
- the arrangement such that said microwave field can produce ionization of at least one of said oxygen and said reactant gas to form a plasma in said tube and produce a temperature of at least 1000.degree. C on the inside wall of the tube whereby a fused layer of said material is formed on said inner wall.
3 more elements
Dependencies are inferred from the claim text.