Optical waveguide grating and method of manufacturing the same
CA 2318119 A1 · Owner: Sumitomo Electric Industries, Ltd. · Inventors: Enomoto, Tadashi; Ishikawa, Shinji; Harumoto, Michiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In an optical fiber (l0), which has a clad region (l2) around a core region (11), of an optical waveguide grating, periodic refractive index variation occurs in a predetermined range (l3) extending in a direction of the optical axis of the core region (ll), the core region (ll) having composition of for , example, GeO2-P2O5-SiO2, the clad region (l2) comprising SiO2 a co-addition , ratio in the core region (ll) being regulated whereby the temperature , dependency of the property thereof is reduced an amount of addition of P2O5 , in the core region (ll) being preferably not less than l/l5 times and not more than l times that of GeO2, and more preferably 0.6-l times that thereof.
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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 8, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 8, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 8, 2021.
- 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.