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Expired Canadian patentCanada

Lightwave systems using optical amplifiers

CA 1303136 C · Owner: American Telephone And Telegraph Company · Inventors: Olsson, Nils Anders

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Abstract, A single frequency lightwave system employs semiconductor optical amplifiers arranged in tandem with suitable noise filtering and isolation between amplifier stages. Feedback control maintains overlap between the signal frequency and one of the passbands of the amplifiers. Either direct detection or coherent detection can be used. Also described is a receiver front end which includes such an amplifier between the incoming signal and a photodetector. Both transmission systems and switching systems are described.

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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

  • Granted June 9, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 9, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 26, 1988
GrantedJune 9, 1992
Term endedJune 9, 2009
Patent numberCA 1303136 C
Classification (IPC)H04B10/00 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedOct 26, 1988Patent grantedJune 9, 1992Term endedJune 9, 2009

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.