Semiconductor optical device
CA 2007383 C · Owner: Ohtoshi, Tsukuru · Inventors: Ohtoshi, Tsukuru; Uomi, Kazuhisa; Chinone, Naoki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A semiconductor optical device in which an optical waveguide is provided on a semiconductor substrate comprises a strained-layer superlattice whereby to show, an extremely small transmission loss. A semiconductor optical device with further improved characteristics is obtainable by using a strained-layer superlattice for a portion required to show a great change in refractive index, such as an optical crosspoint switch portion as, well as for the optical waveguide. The strained-layer superlattice comprises a first semiconductor layer and a second semiconductor layer having a narrower band gap and a greater lattice constant as compared with the first semiconductor layer, the two layers being …
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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 9, 1990 and granted May 19, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 9, 2012.
- 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.