Iridium fiber draw induction furnace
AssigneeAT&T Bell Laboratories
InventorJames W. Fleming, Jr.
Life of this patent
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Abstract
An induction furnace for reflowing a portion of an optical preform in order to draw a lightguide fiber therefrom. The furnace has an axially located tubular iridium susceptor which is centrally disposed within a beaker and a sleeve is positioned concentrically around the susceptor. The sleeve is surrounded by an insulating grain. A high frequency coil is energized to couple its electromagnetic field to the iridium susceptor to heat and reflow a portion of the preform in order to draw the fiber therefrom. The furnace housing is sealed to provide an inert, non-oxidizing atmosphere for the iridium susceptor.
Claims6
An induction furnace for heating a silica lightguide preform to a temperature in the range of approximately 1900.degree. C. to 2200.degree. C. in order to draw lightguide fiber therefrom, comprising:
- a) a housing which includes a sidewall, a top and a base, each of said top and base having an aperture, said apertures being vertically aligned;
- b) a tubular member having a top and bottom aperture in alignment with said housing apertures, said tubular member being supported on said housing base and enclosed by said housing sidewall, said tubular member comprises:
- i) a beaker having a sidewall and a base, said base having an aperture which is in alignment with said housing apertures;
- ii) a tubular susceptor having a circular bore of a diameter sufficient to receive therein a preform without said preform contacting said susceptor, said susceptor being supported and surrounded by said beaker;
- iii) insulating solid material disposed between said susceptor and said beaker;
- and
- c) an RF induction coil enclosed by said sidewall of said housing and surrounding said beaker;
- wherein
- d) the tubular susceptor consists essentially of iridium.
Dependencies are inferred from the claim text.