Switch for selectively switching optical wavelengths
CA 2000646 C · Owner: Cheung, Kwok-Wai · Inventors: Cheung, Kwok-Wai
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A 2x2 optical switching element is described. Illustratively the switching element, includes first and second inputs for receiving optical radiation and first andsecond outputs for transmitting optical radiation. The switching element also includes mode conversion means for selectively switching optical radiation of a specific wavelength arriving via one of the inputs to either or both outputs by selectively controlling the conversion of the radiation at the specific wavelength from one mode to another. An NxN swithc may be formed from an array of the 2x2 switching element.
Read the whole patent
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 October 13, 1989 and granted June 22, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 13, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 13, 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.