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Expired Canadian patentCanada

Optical structures with two optical guidance paths

CA 2180407 C · Owner: Tarbox, Eleanor Joan · Inventors: Tarbox, Eleanor Joan

CIPO record

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Abstract From the Canadian patent

An optical structure having two optical guidance paths between which coupling occurs in a band about one predetermined wavelength is manufactured by providing an optical structure having two optical guidance paths with respective propagation constants 12', 14' which vary differently with wavelength and coincide at one given wavelength .lambda.' arranged such that coupling occurs between said optical guidance paths in a band about said one given wavelength and subjecting the or at least one of the guidance paths which includes a radiation responsive refractive index changing dopant to radiation to change the propagation constant thereof until said one given wavelength equals said one …

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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 July 3, 1996 and granted September 3, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 3, 2016.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 3, 2018.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 3, 1996
GrantedSeptember 3, 2002
Term endedJuly 3, 2016
Patent numberCA 2180407 C
Classification (IPC)G02B6/12 +2 more

Timeline

Timeline From CIPO dates

1997199920012003200520072009201120132015Application filedJuly 3, 1996Patent grantedSep 3, 2002Term endedJuly 3, 2016

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