Optical signal processor, method of its control, method of its designing, and method of its production
CA 2126306 C · Owner: Kawachi, Masao · Inventors: Takiguchi, Koichi; Kawachi, Masao; Jinguji, Kaname
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical signal processor according to the present invention is an optical circuit of a lattice configuration. Its basic circuit structure comprises 3 dB directional couplers two optical waveguides with equal optical path lengths and two optical waveguides with different optical path lengths (an optical path difference of about 1 to 50 mm). Phase controllers for performing phase shift are provided on the optical waveguides. The portions with equal optical path lengths function as variable directional couplers and variable directional couplers having arbitrary coupling rates can be constructed by changing the phase controllers on the optical waveguides with equal optical path lengths. As …
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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 June 20, 1994 and granted December 28, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 2016.
- 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.