Optical waveguide and method for its manufacture
CA 2013849 C · Owner: Nortel Networks Limited · Inventors: Kalnitsky, Alexander; Ellul, Joseph Paul; Boothroyd, Albert Roy
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical waveguide is made by forming a layer of SiO2 on a substrate and implanting a region of the SiO2 layer with Si ions to define a region containing a stoichiometric excess of Si which defines a region having an elevated refractive index surrounded by a region having a lower refractive index. The resulting optical waveguide is stable at the high temperatures required for many semiconductor processing methods, and is useful for optical interconnection in integrated optical and optoelectronic devices.
Read the whole patent
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 4, 1990 and granted August 25, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 4, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 4, 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.