High speed optical switching device including a capacitance structure
CA 2117806 C · Owner: British Telecommunications Public Limited Company · Inventors: Wake, David; Moodie, David Graham; Rodgers, Paul Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A high speed optical switching device (1) comprises a waveguide arrangement incorporating a pn junction, with a large bondpad (11) for the purposes of increasing the capacitance presented by the device. Data and control signals can be input at an input port (8) of the waveguide arrangement presence of the control signal operating to modify the optical path length of the device for the data signal. By incorporating the device in an interferometer arrangement or by exploiting a Fabry-Perot cavity of the device, it can be used to transmit the data signal selectively for instance so as to demultiplex a time multiplexed optical communications signal. The high capacitance provides very short …
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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 April 13, 1993 and granted June 1, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 13, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 13, 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
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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.