Multi-branch digital optical switch
CA 2136752 C · Owner: Tait, William Charles · Inventors: Brown, James Charles, Jr.; Mohapatra, Sarat Kumar; Tait, William Charles
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multi-branch digital optical switch (10) having three branch waveguides through which light may exit. The multi-branch digital optical switch includes a main waveguide (12) two side branch , waveguides (16,18), and one center branch waveguide (14). The two side branch waveguides diverge symmetrically from the center branch waveguide at angles which are sufficiently small to allow modal evolution through the switch to be substantially adiabatic. Electric fields are used to raise the index of refraction of one side branch waveguide above the index of the center branch waveguide and to tower the index of refraction of the other side branch below the index of the center branch waveguide. …
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 June 7, 1993 and granted April 15, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 7, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 7, 2015.
- 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.