Method for depositing a coating layer on an optical fiber while it is being drawn and device for its implementation
AssigneeFrance Telecom
InventorsYves Ruello, Benoit Cadier
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Abstract
A method for the deposition of a coating layer on an optical fiber while it is being drawn. The coating layer is designed to reduce the permeability of the optical fiber to water vapor and therefore to increase its lifetime. The method is characterized in that it consists in carrying out a decomposition of a gas mixture of boron halogenide and hydrogen and/or boron halogenide and ammonia gas by a microwave plasma-assisted addition of energy and in that the operation is conducted in the presence of a carrier gas in order firstly to carry the gas mixture to a reaction medium and secondly to activate the plasma.
Claims19
Method for the deposition of a coating layer on an optical fiber while it is being drawn, said coating layer being designed to improve the imperviousness and lifetime of said optical fiber, the method consisting in decomposing a gas mixture of boron halogenide and hydrogen and/or boron halogenide and ammonia gas by means of a microwave plasma-assisted addition of energy, characterized in that the operation of deposition is performed under a pressure of less than 5 mbar, in the presence of a carrier gas in order firstly to carry said gas mixture to a reaction medium and, secondly, to activate the plasma.
Optical fiber coated with a coating layer designed to increase its imperviousness and its lifetime, characterized in that the coating layer comprises boron and has a thickness of 100 to 1000 Å.
Optical fiber with a coating layer designed to increase its imperviousness and its lifetime, characterized in that the coating layer comprises a combination of boron and boron nitride wherein the coating layer has a thickness of 100 to 1000 Å.
Dependencies are inferred from the claim text.