MCVD method of making a low OH fiber preform with a hydrogen-free heat source
AssigneeAT&T Corp.
InventorsFred P. Partus, Gordon A. Thomas
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Abstract
A method for making a glass preform substantially free of OH impurities is disclosed. The method comprises the steps of introducing a moving stream of a vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube, while generating a hydrogen-free isothermal plasma on an outer surface of the tube to react the mixture and produce a glassy deposit on an inner surface of the tube. The method uses a plasma torch or a radio frequency furnace.
Claims13
A method for making a glass preform substantially free of OH impurities, comprising the steps of:
- introducing a moving stream of a vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube;
- and
- generating a hydrogen-free isothermal plasma on an outer surface of the tube, whereby the mixture reacts and a glassy deposit is produced on an inner surface of the tube thereby forming a glass preform.
A method for making a glass preform substantially free of OH impurities, comprising the steps of introducing a moving stream of a vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube and heating an outer surface of the tube, whereby the mixture reacts and a glassy deposit is produced on an inner surface of the tube to thereby form a glass preform substantially free of OH impurities, the improvement comprising the steps of:
- using a hydrogen-free isothermal plasma torch for the heating of the outer surface of the tube.
A method for making a glass preform substantially free of OH impurities, comprising the steps of introducing a moving stream of a vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube and heating an outer surface of the tube, whereby the mixture reacts and a glassy deposit is produced on an inner surface of the tube to thereby form a glass preform substantially free of OH impurities, the improvement comprising the steps of:
- using a radio frequency furnace for the heating of the outer surface of the tube in a substantially hydrogen free atmosphere.
Dependencies are inferred from the claim text.