Alcatel

Alcatel Fibres Optiques

Alain Drouart

Pierre Ripoche

Beno&icirc;t Gouez

Yves Lumineau

Jean-Florent Campion

Max Matau

Benoit Gouez

Pascal Mazabraud

Bernard Jouvenel

Bernard Wurier

Jean-Forent Campion

A method of fabricating an optical fiber preform is disclosed which includes a step of outside deposition of silica possibly doped with at least one dopant by injecting at least one substance in the form of silica or a precursor of silica in the vicinity of a heating area created by a heating system during at least one pass of an injector system and the heating system along a longitudinal axis of the preform during which the relative positions of the injector and heating systems ore adjusted so that silica is deposited in the heated area regardless of the position of the heating system.

Method of fabricating an optical fiber preform including outside deposition of silica, possibly doped silica

Natural or synthetic silica is deposited on a preform set into rotation in front of a plasma torch which moves back and forth substantially parallel to a longitudinal direction of the preform, a first feed duct feeds the plasma with grains of natural or synthetic silica while a second feed duct feeds the plasma with a fluorine or chlorine compound, preferably a fluorine compound, mixed with a carrier gas. Any sodium or lithium contained in the grains of natural or synthetic silica react with the fluorine or chlorine of the fluorine or chlorine compound, thereby making it possible to improve the optical quality of fibers drawn from a preform built up with natural or synthetic silica, and to do so at reduced cost.

Method of purifying natural or synthetic silica, and application thereof to depositing purified natural or synthetic silica on an optical fiber preform

The invention relates to manufacturing glass fiber preforms. It relates to a method comprising rotating preform about its own axis, and displacing a plasma torch in translation relative to the preform in a direction parallel to the axis of the preform, the axes of the flame and of the preform and being offset by a certain distance, and then inserting glass powder into the plasma flame under gravity. According to the invention, the glass powder is accelerated before penetrating into the plasma flame by means of an accelerator gas, and the offset distance between the axes is reduced with increasing acceleration of the powder. The invention is applicable to manufacturing glass fibers, and in particular optical fibers.

Apparatus for gravity feeding powder to a plasma torch for manufacturing glass fiber performs

Method of purifying silica and depositing on an optical fiber preform

Method of making a glass fiber preform with adjusting a spacing while increasing acceleration of a starting glass powder

Butt welding optical fiber preforms with a plasma torch

A device for drawing down an optical fiber preform (2) connected at one end to a feed rod (3) having an equal or smaller diameter. A chamber (11) in which the preform is drawn has an upper part (11A) with an opening (12). The opening engages the preform to seal the chamber. An enclosure (5) has a seal (6) at its upper part (5A) for sealing around the feed rod. A lower part (5B) of the enclosure contacts the upper part of the chamber to seal the chamber while the feed rod is passing through the opening.

Device for drawing down an optical fiber preform

A method of using a plasma to build up an optical fiber preform consists in injecting hydroxyl ions in a controlled manner into the build-up silica that is deposited on the preform. The invention is applicable to the manufacture of optical fibers, in particular monomode fibers.

Method of building up an optical fiber preform by plasma deposition, and

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Nanterre, France

Alain Drouart