Optical waveguide device
CA 2133300 C · Owner: Ichikawa, Junichiro · Inventors: Shinriki, Takashi; Kobayashi, Masanobu; Minowa, Junichiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical waveguide device usable as an optical wave-modulator and having a reduced DC drift includes a LiNbO3 substrate, an optical waveguide formed in a front surface portion of the substrate, a dielectric layer covering the front surface of the substrate and the optical waveguide surface, and an electrode system arranged on the dielectric layer, the dielectric layer comprising a matrix component consisting of an amorphous SiO2 and a doping element component consisting of Li and/or Nb; and having a refractive index lower than that of the amorphous SiO2 matrix free from the doping element component.
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 September 29, 1994 and granted April 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 29, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 29, 2016.
- 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.