Optical fiber amplifier
CA 2019253 C · Owner: Fujitsu Limited · Inventors: Takeda, Keiko; Yoshizawa, Sakae; Sasaki, Kazuya
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical fiber amplifier is disclosed wherein pumping light and signal light are introduced into an optical fiber doped with a rare-earth element to directly amplify the signal light. The optical fiber amplifier of the invention comprises means constituted from a reflecting film, a fiber loop or the like for causing pumping light to pass by a plurality of times in the doped fiber. Due to the provision of the reflective film or the fiber loop, pumping light can be utilized efficiently, and the amplification factor of the optical fiber amplifier is improved.
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 June 19, 1990 and granted January 11, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 19, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 19, 2012.
- 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.