Method for collapsing a hollow substrate tube into a rod-like preform while heating
AssigneeDraka Fibre Technology B.V.
InventorsDennis Robert Simons, Igor Milicevic
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Abstract
The present invention relates to a method for collapsing a hollow substrate tube into a rod-like preform while heating by reciprocating a heating element along the length of the substrate tube. The present invention is characterized in that a constant electric power is supplied to the heating element during collapsing.
Claims4
A method for collapsing a hollow substrate tube into a rod-like preform while heating by reciprocating a heating element along the length of the substrate tube, characterized in that a constant electric power is supplied to the heating element during collapsing.
A method according to any one of the preceding claims, characterized in that the internal surface of the substrate tube comprises dopant in an amount of at least 4 mol. %.
A method for collapsing a hollow substrate tube into a rod-like preform while heating by reciprocating a heating element along the length of the substrate tube, characterized in that an etching gas is passed through the central opening of the hollow substrate tube, with a constant electric power being supplied to the heating element, just before the duct closes spontaneously to form a rod-like preform.
Dependencies are inferred from the claim text.