Technique for fabricating single mode lightguide soot-forms
AssigneeAT&T Technologies, Inc.
InventorsRonald E. Fanucci, Maria J. Yuen
Life of this patent
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Abstract
A torch (24) used in the Vapor-phase Axial Deposition (VAD) process to form small diameter cores for single mode lightguide preforms. The torch (24) is comprised of a plurality of concentrically mounted, spaced, glass tubes (62, 63, 64, 65, 66) through which reactants and combustible materials are passed. A tapered shroud (68) is mounted about the end of the torch (24) and a shield gas directed along the inner surface thereof to confine and direct the gases and reactants to the surface of the soot form (12).
Claims6
A method of forming a core of a single mode lightguide soot-form, comprising the steps of:
- directing combustible gases and reactants through a plurality of spaced, concentric cylinders;
- igniting the combustible gases to form a flame to heat the reactants to form a soot stream;
- forming a tapered shield of gas at the output of the concentric cylinders to confine and direct the soot stream at a starting member to initially deposit the soot-form core thereon;
- and
- moving the starting member, with the soot-form core thereon, relative to the soot stream while depositing soot on the core to increase the length thereof.
A method of fabricating a single mode lightguide preform, comprising the steps of:
- (a) directing combustible gases and reactants through a plurality of spaced, concentric cylinders;
- (b) igniting the combustible gases to form a flame to heat the reactants to form a soot stream;
- (c) forming a tapered shield of gas at the output of the concentric cylinders to confine and direct the soot stream as a bait rod to fabricate the soot-form;
- (d) consolidating the soot-form into a clear glass billet;
- (e) stretching the billet into an elongated rod;
- (f) positioning the rod inside a glass tube;
- and (g) heating the tube, with the rod therein, to form the single mode lightguide preform.
Dependencies are inferred from the claim text.