Method and apparatus for automatic compensation of first-order polarization mode dispersion (pwd)
CA 2245303 C · Owner: Fishman, Daniel A. · Inventors: Wilson, David L.; Heismann, Fred Ludwig; Fishman, Daniel A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The effect of polarization mode dispersion that an optical signal experiences as it propagates through an optical transmission fiber is compensated for at a receiver using a birefringent compensator in which, the compensator automatically and adaptively generates a level of differential time delay that substantially equals the differential time delay that the optical signal experiences, but of different sign and, therefore, essentially cancels out the undesired delay.
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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 August 19, 1998 and granted December 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 19, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 19, 2020.
- 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.