Differential phase modulation in an optical fibre communication system
CA 1263445 C · Owner: Plessey Overseas Limited · Inventors: Dakin, John P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical fibre communication system in which modulator means is provided at the transmitter end of the system for modulating the relative phase between orthogonally polarised signals derived from a coherent light source in accordance with data or information to be transmitted over an optical fibre communication path to the receiver end of the system where the signals will be demodulated. In order to reduce noise resulting from delay differentials between polarised signals transmitted over the optical fibre path it is preferred to arrange that the communication path includes sections of polarisation maintaining optical fibre which are angularly rotated through 90 or thereabouts relatively …
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
- Granted November 28, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 28, 2006.
- 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.