Writing gratings
CA 2227493 C · Owner: Nortel Networks Corporation · Inventors: Phillips, Nicholas John; Napier, Bruce
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A progressive method of writing a long grating in a substrate using a pulsed interference fringe pattern. The substrate is moved through the fringe pattern while being continuously illuminated with light of a different wavelength to produce a diffracted beam whose phase is monitored to produce a control signal that regulates the pulsing of the writing beam to ensure that the fringe pattern is present only when it is in correct registry with the grating being written.
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 20, 1998 and granted September 19, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 20, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 20, 2020.
- 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.