Optical filter fabrication method and apparatus, optical filter, fiber holder with spiral groove, and phase mask
CA 2242371 C · Owner: Terao, Yoshitaka · Inventors: Nomoto, Tsutomu; Nishiki, Akihiko; Terao, Yoshitaka
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical filter is manufactured by placing a photosensitive optical fiber in a spiral arrangement on a fiber holder, preferably having a spiral groove for holding the fiber, and exposing the fiber to ultraviolet light through a phase mask having a spiral diffraction grating forming an in-fiber Bragg grating. The fiber can be conveniently scanned by an ultraviolet beam as the fiber holder and phase mask turn on a rotating stage. The fiber can be compactly packaged between the fiber holder and a cover. The fiber holder and cover can be formed by coating a substrate with layers of polymer material the spiral groove, being formed by photolithographic patterning of one of the layers.
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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 July 6, 1998 and granted June 24, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 6, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 6, 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.