Optical fiber amplifier and optical communication system using the same
CA 2369906 C · Owner: Nippon Telegraph And Telephone Corporation · Inventors: Mori, Atsusi; Shimizu, Makoto; Masuda, Hiroji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to the following four structures for attaining a flat gain spectrum over a wide wavelength region. The first structure relates to a Roman amplifier where a tellurite fiber is pumped with two wavelengths having a predetermined difference. The second structure relates to a Raman amplifier or an optical communication system employing a tellurite fiber and a silica fiber. The third structure relates to an optical fiber amplifier employing an Erbium-doped tellurite fiber of which Erbium concentration is low. The fourth structure relates to an optical fiber amplifier employing a rare-earth doped fiber such as the Erbium-doped fiber and a tellurite fiber.
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 31, 2002 and granted May 15, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 31, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 31, 2024.
- 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.