Optical device having switching function
CA 2177789 C · Owner: Uetsuka, Hisato · Inventors: Uetsuka, Hisato; Arai, Hideaki; Akiba, Kenji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical device having a switching function has a waveguide filter for switching an input signal light including at least one specific wavelength to be either transmitted or reflected. The input signal lights of wavelengths .lambda.1 to .lambda.n are transmitted to the input waveguide. When the waveguide filter is off the signal, lights of all wavelengths are transmitted to the output port. when the waveguide filter is on, the signal lights of wavelengths .lambda.2 to .lambda.n are transmitted but the signal, light of wavelength .lambda.1 is reversed and output to the drop port. If the thin film heaters are off a signal light of, wavelength .lambda.1 is output (dropped) from the drop …
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 May 30, 1996 and granted January 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 30, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 30, 2018.
- 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.