Coherent optical communication system with fsk heterodyne or homodyne detection and little influence by distortion of a modulated optical signal
CA 1232325 A · Owner: Nec Corporation · Inventors: Shikada, Minoru; Emura, Katsumi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A laser (21) is frequency modulated by an electrical modulating signal of a bit rate into a modulated signal of a first and a second modulated frequency. A combination of an optical mixer (27) and an optical detector (31) carries out optical heterodyne or homodyne detection on the modulated optical signal to produce a detected signal having a first and a second frequency component. A component separator (32) is for selecting only one of the components from the detected signal. A detector (33) detects the selected component to produce a demodulated electrical signal representative of the modulating signal. The laser is preferably a semiconductor laser. More preferably the semiconductor, …
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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 February 2, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 2, 2005.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.