Wavelength multiplexer/demultiplexer with varied propagation constant
CA 2236970 C · Owner: Bhagavatula, Venkata A. · Inventors: Bhagavatula, Venkata A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Wavelength dispersion in an optical demultiplexer (10) is accomplished by varying propagation constants of a central pathway (16) traverse to the direction of wavefront propagation through the central pathway (16). The propagation constant can be varied by changing the dimensions or refractive qualities of the central pathway, which can be formed as a common waveguide (36) or as plurality of individual waveguides (16).
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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 January 6, 1997 and granted December 3, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 6, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 6, 2019.
- 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
Timeline From CIPO dates
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.