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Expired Canadian patentCanada

Method and apparatus using polarisation optical time domain reflectometry for security applications

CA 2471803 C · Owner: Senstar Corporation · Inventors: Haran, Francis M.

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Abstract From the Canadian patent

A preferred apparatus and method is presented in which a distributed fiber optic sensor is used in order to detect a disturbance along its length. A pulse of polarized light is launched into an optical fiber; as the pulse propagates along the optical fiber it continuously loses a small portion of its energy due to Rayleigh backscatter. The Rayleigh backscattered light is analyzed using a polarization sensitive element such as a fiber polarizer. The dynamics of the time dependence of the polarization analyzed backscattered light is used to ascertain if there has been a disturbance along the length of the optical fiber. This technique can be used for applications in areas such as fiber optic …

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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 June 21, 2004 and granted September 25, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 21, 2024.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 21, 2026.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 21, 2004
GrantedSeptember 25, 2012
Term endedJune 21, 2024
Patent numberCA 2471803 C
Classification (IPC)G08B13/22 +2 more

Timeline

Timeline From CIPO dates

2005200720092011201320152017201920212023Application filedJune 21, 2004Patent grantedSep 25, 2012Term endedJune 21, 2024

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