Method for producing glass preform for optical fiber
CA 1283543 C · Owner: Sumitomo Electric Industries, Ltd. · Inventors: Tanaka, Shigeru; Kyoto, Michihisa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides a method for producing a GeO2-SiO2 type glass preform for an optical fiber. The method comprises dehydrating a porous soot preform made of GeO2-SiO2 fine glass particles in an atmosphere of oxygen containing a fluorine-containing compound at such a temperature that the preform does not drastically shrink, and then sintering the soot preform in an atmosphere comprising helium at such a temperature that the preform is made transparent. By this method, contamination with impurities, residual water and bubbles in the optical fiber and irregularities of the surface of the optical fiber are greatly reduced.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted April 30, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 30, 2008.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.