Process for the production of an optical waveguide preform
CA 2058183 C · Owner: Alcatel N.V. · Inventors: Weber, Dieter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In the process for the production of an optical waveguide preform, in which the cladding layer is applied as a tubular powder layer onto a cylindrical glass core rod and is densified by heating the powder, layer has a relative density of approximately 6 percent, which is increased to 25-50 percent during the stabilization process. In order for this process to proceed without damage to the preform, the powder layer is initially heated at a low heating rate. From approximately 150°C, the heating rate is increased until a higher temperature is reached.
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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
- Filed December 20, 1991 and granted October 7, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 2013.
- 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
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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.