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Expired Canadian patentCanada

Photosensitization of optical fiber and silica waveguides

CA 2115906 C · Owner: Hill, Kenneth O. · Inventors: Hill, Kenneth O.; Johnson, Derwyn C.; Albert, Jacques

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A method of fabricating a strongly photosensitive optical waveguide is comprised of locally heating at least a portion of a weakly photosensitive optical waveguide for a period of time sufficient to increase the density of defects associated with photosensitivity in the heated portion of the waveguide core.

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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 February 17, 1994 and granted December 25, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 17, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 17, 2016.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 17, 1994
GrantedDecember 25, 2001
Term endedFebruary 17, 2014
Patent numberCA 2115906 C
Classification (IPC)C03C4/04 +2 more

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedFeb 17, 1994Patent grantedDec 25, 2001Term endedFeb 17, 2014

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.