Optical filter multiplexing/demultiplexing device
CA 2229956 C · Owner: Si, Y. Calvin · Inventors: Duck, Gary Stephen; Cheng, Yihao; Si, Y. Calvin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical filter is provided having first and second graded index (GRIN) lensespreferably disposed in a coaxial relationship so that they have a common optical axis. Each of the GRIN lenses have an endface providing a port at predetermined location. The ports are disposed on opposite sides of the optical axis and each of the ports are substantially equidistant from the optical axis so as to be oppositely offset from the optical axis by a same amount. The filter also includes an optical interference filter disposed between other endfaces of the first and second graded index lenses. By changing the location of the ports by a same small amount the center wavelength of the filter, changes by a …
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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 February 20, 1998 and granted October 16, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 20, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 20, 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
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.