Optical modulators as monolithically integrated optical isolators
CA 2128839 C · Owner: American Telephone And Telegraph Company · Inventors: Liou, Kang-Yih; Koyama, Fumio; Koch, Thomas Lawson
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, An apparatus and technique for providing isolation for a signal source utilizing two or more modulators is described. In particular, the apparatus generates a timed sequence of "open gates" that are synchronized to the data signal which permit transmission in a forward direction and which attenuate a reverse direction signal. Another embodiment attenuates primarily reflected light signals by utilizing a passive waveguide and a modulator. The passive waveguide provides a propagation delay such that signals reflected from its end facet are attenuated by the modulator. The apparatus is suitable for use as an isolator for a light source in a high-speed optical fiber data transmission …
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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 July 26, 1994 and granted May 18, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 26, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 26, 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
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.