Fiber optic amplifier
CA 2042697 C · Owner: Fujitsu Limited · Inventors: Inagaki, Shinya; Takeda, Keiko; Tagawa, Kenji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical fiber doped with Er is provided at its both end portions with a pair of 1.25µ m band reflecting filters such that the distance therebetween becomes the resonator length for a light beam of 1.25µ m band. When a pumping light beam of a wavelength of 0.8 µ m band is introduced into the optical fiber laser, oscillation at 1.25µ m band is produced whereby the, energy level of Er in an excited state is lowered and a signal light beam of a wavelength of 1.55µ m band can be optically amplified with high efficiency. Another fiber optic amplifier in which a pair of 0.98µ m band reflecting filters are disposed at both end portions of an optical fiber doped with Yb and Er such that the …
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 15, 1991 and granted August 16, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 15, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 15, 2013.
- 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.