Laser direct writing of planar lightwave circuits
CA 2336091 A1 · Owner: Luther-Davies, Barry · Inventors: Charters, Robbie; Ladouceur, Francois; Luther-Davies, Barry
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A laser beam with an annular or ring shaped intensity distribution such as a , TEM01* beam, is scanned across the surface of a photosensitive thin film to directly produce changes of refractive index in selected regions of the film. This method is suitable for producing channel waveguides for planar lightwave circuits, where the refractive index profile (solid curve) of such a waveguide is more uniform than the prior art refractive index profile (dashed curve) produced by a TEM00 laser beam, and has a reduced bend loss.
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 July 2, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 2, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 2, 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.