Optical waveguide multiplexer for optical fiber amplifiers
CA 2127163 C · Owner: Nec Corporation · Inventors: Yokoyama, Jun
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical waveguide multiplexer for use in optical fiber amplifiers or the like, which is simple in configuration, permits manufacturing at high productivity and is reduced in size and moreover susceptible to little insertion loss, is to be realized. A multiplexer-branching filter is provided with first to fourth input/output (I/O) terminals. Part of an optical signal emitted from the first I/O terminal is reflected by a branching film formed over one face of a glass plate, and led to the second optical I/O terminal. The rest of the optical signal penetrates the glass plate, and further penetrates an optical multiplexing film, formed on the other face to be led to the third optical I/O …
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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 30, 1994 and granted July 14, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 30, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 30, 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
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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.