Method of fabricating bragg gratings using a silica glass phase grating mask
CA 2087511 C · Owner: Johnson, Derwyn C. · Inventors: Hill, Kenneth O.; Johnson, Derwyn C.; Malo, Bernard Y.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An index grating is imprinted in the core of an optical fiber using a specially designed silica glass phase grating mask. The phase mask is held in close proximity to the optical fiber. Laser irradiation of the phase mask with ultraviolet light at normal incidence imprints (photoinduces) into the optical fiber core the interference pattern created by the phase mask.
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 January 18, 1993 and granted June 6, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 18, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 18, 2015.
- 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.