Method for manufacturing a primary preform for optical fibres
AssigneeDraka Comteq B.V.
InventorsJohannes Antoon Hartsuiker, Igor Milicevic, Mattheus Jacobus Nicolaas Van Stralen, Eric Aloysius Kuijpers
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Abstract
A method for manufacturing a primary preform for optical fibres including surrounding at least part of a hollow substrate tube with a furnace set at a temperature T0, supplying doped or undoped gases to the inside of the tube, creating a reaction zone to promote deposition, and moving the zone back and forth along the length of the tube between to form at least one preform layer, wherein the temperature of the furnace is varied linearly as a function of the thickness of the at least one preform layer to compensate for temperature increases of the tube during deposition.
Claims20
A method for manufacturing a primary preform for optical fibres using an internal vapour deposition process, comprising the steps of:
- i) providing a hollow glass substrate tube having a supply side and a discharge side;
- ii) surrounding at least part of the hollow substrate tube with a furnace set at a temperature T0,
- iii) supplying doped or undoped glass-forming gases to the interior of the hollow glass substrate tube via the supply side;
- iv) creating a reaction zone with conditions such that deposition of glass on the inner surface of the hollow glass substrate tube takes place;
- and
- v) moving the reaction zone back and forth along the length of the hollow glass substrate tube between a reversal point located near the supply side and a reversal point located near the discharge side to form at least one preform layer on the inner surface of the hollow glass substrate tube, the at least one preform layer comprising several glass layers;
- wherein the temperature of the furnace surrounding the hollow glass substrate tube is varied linearly as a function of the thickness of the at least one preform layer in the radial direction during at least part of step v) to compensate for the temperature increase of the hollow glass substrate tube during the deposition process.
Dependencies are inferred from the claim text.