Alcatel

Alcatel Fibres Optiques

Draka Comteq B.v.

Alcatel Cable

Pierre Ripoche

Alain Drouart

Beno&icirc;t Gouez

Yves Lumineau

Patrick Humbert

Jacques Goudeau

Jean-Florent Campion

Bernard Jouvenel

Benoit Gouez

Max Matau

Bernard Wurier

Joël Landi

Jean-Forent Campion

Daniel Coelho

Jo&euml;l Landi

Jean-Pascal Dumont-Monnet

The invention relates to apparatus for supporting a preform manufactured in an installation for manufacturing or building up preforms having supporting cores, said installation including at least rotation means having a horizontal axis of rotation and two mounting points between which the supporting core of the preform to be manufactured or built up is mounted, plasma-torch and material-supply means disposed radially relative to said supporting core and being mounted to move in axial translation relative to and parallel to the supporting core so as to make said preform around said supporting core, said apparatus being wherein it includes controlled support means constituting additional localized abutment points between said mounting points for said preform being manufactured or built up.

Apparatus for supporting a preform having a supporting core

The invention relates to an inductive thermal plasma torch comprising a confinement tube that comprises, longitudinally in relation to the tube, metal fingers which are insulated from each other, an ignition device that comprises an igniter () and an igniter support (), the purpose of the igniter () being to initiate a discharge in the plasma of the torch, the support having an electrically conductive end () which is connected to the electrical earth () of the plant and another, electrically insulating, end () which carries the igniter, the ignition device also comprising an electrically conductive connection () connecting the igniter () to the electrically conductive end () of the support so that the igniter is able to initiate the discharge in the plasma, the electrically conductive connection () having a section that is sufficiently narrow to limit the intensity of the current capable of passing through the igniter () in order to avoid electrical arcing by capacitive discharge between the ignition device and another part of the torch.

Inductive thermal plasma torch

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 method includes axially modulating at least one plasma build-up pass in order to improve the opto-geometrical properties of the preform. The modulation preferably takes place during the final passes of plasma build-up and takes place by modulating the build-up grain flow rate. The diameter of the preform is evaluated ( ), and a build-up control device ( ) regulates grain flow rate ( ) in application of the above method.

Modulating a diameter-increasing step of a fiber preform with no modulation prior to a predetermined diameter

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

A method and associated apparatus for increasing the over cladding rate in perform production while maintaining the integrity of the glass quality of the cladding. The method and apparatus are designed to utilize the full capacity of the generator to thereby improve the overall deposition speed without sacrificing the glass quality. In particular, it is estimated that the process of the present invention will increase the deposition speed by approximately 50% and still obtain suitable glass quality. This object is achieved by utilizing two plasma torches, instead of just one, that are driven by the same power generator. The process of over-cladding a perform includes the steps of supporting the perform on a lathe; providing first and second plasma torches having nozzles angled toward the perform; powering the first and second plasma torches with a common generator such that the plasma torches create plasma flames directed toward a surface of the perform; introducing a quartz sand at a junction between the first plasma torch and the surface of the perform to fuse the quartz sand on the surface of the perform; and moving the perform with respect to the plasma torches. According on one aspect of the invention, the second plasma torch is provided upstream of the first plasma torch so as to preheat the surface before the fusing of the quartz sand by the first plasma torch. According to a second aspect of the invention, the second plasma torch is located downstream of the first plasma torch to post-heat the quartz sand after the initial fusing by the first plasma torch. According to a third aspect of the invention, the quartz sand is introduced at a junctions between the surface of the perform and both of the plasma torches to fuse the quartz sand with both the first and second plasma torches simultaneously.

Plasma overcladding process and apparatus having multiple plasma torches

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

Apparatus for controlling the sag of a preform in an installation

Butt welding optical fiber preforms with a plasma torch

The present invention relates to an induction plasma torch of the type used in plasma deposition methods for depositing pure or doped silica when manufacturing preforms for optical fibers, the plasma torch comprising:

Induction plasma torch

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.

Growing community of inventors

Pithiviers, France

Pierre Ripoche