Optical wavelength multiplexer/demultiplexer and demultiplexer/remultiplexer
CA 2003193 A1 · Owner: Buhrer, Carl F. · Inventors: Buhrer, Carl F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multichannel wavelength demultiplexer has two or more cascaded birefringent filter stages for dividing an input signal consisting of a plurality of adjacent channels of optical signals among a number of outputs each of said filter stages having a transmission function with even symmetry about optical frequencies at the centers of both the longest and the shortest wavelength channels. This symmetry, common to all transmission functions, permits all birefringent filter stages to be constructed from sequences of the same one size crystal element, thereby greatly lowering the cost of construction because solely one size crystal element is fabricated tested and assembled. A multichannel …
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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 November 17, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 17, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 17, 2011.
- 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.