Optical switch
CA 2210536 C · Owner: British Telecommunications Public Limited Company · Inventors: Manning, Robert John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical switch includes a semiconcuctor gain medium and inputs for an optical control signal applied to the semiconductor gain medium. The switch has a pair of arms (31 32) arranged in a Mach-Zehnder configuration. A semiconductor gain medium (SOA1 SOA2) is connected in each arm. A fixed phase shifting element PE is also connected in one arm. Control signals are applied to each of the semiconductor gain media. There is a delay between the control signals selected so that a desired one of the optical pulses experiences a differential phase shift and so we switch to a different output of the multiplexer. In one example the semiconductor gain media are provided by discrete semiconductor …
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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 January 16, 1996 and granted September 26, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 16, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 16, 2018.
- 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.