High-speed polarization scrambler with adjustable chirp
CA 2200236 C · Owner: Heismann, Fred Ludwig · Inventors: Smith, Robert W.; Heismann, Fred Ludwig
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Two separate electrooptic phase modulators are used in a modified Mach-Zehnder interferometer to vary the absolute and relative optical phases of two orthogonally polarized modes of an input signal independently of each other. A conventional Y-branch splitter on lithium niobate splits the input signal equally into the two waveguide phase modulators and an external polarization splitter recombines the two phase modulated signals in orthogonal polarization states. The polarization in the interferometer is maintained by connecting the outputs of the two phase modulators to polarization maintaining fibers. An alternate embodiment of the present invention uses an additional 3-dB directional …
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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 March 18, 1997 and granted September 19, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 18, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 18, 2019.
- 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.