Optical polarization modulator employing interferometric structures
CA 2040936 C · Owner: Bradley, Piero John · Inventors: Bradley, Piero John; Costa, Bruno; Calvani, Riccardo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical polarization modulator has an interferometric structure including, in at least one of two branches, a device causing the signal fractions in the two branches to assume an amplitude ratio depending on the value taken by a control signal, and a desired relative phase. In one embodiment, the amplitude modulators are multiple quantum well asymmetric cavity Fabry-Perot devices biased in a complementary manner by binary signals the, levels of which are associated with voltage values such as to bring the devices to maximum absorption or maximum reflectivity conditions respectively; thus for each signal level only one of the two cavities reflects part of the received radiation. The …
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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 22, 1991 and granted April 16, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 22, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 22, 2013.
- 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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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.