Automatic gain control for free-space optical telecommunications links
CA 2229350 C · Owner: Javitt, Joel I. · Inventors: Javitt, Joel I.; Rutledge, Christopher L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Free-space optical transmission of analog information is facilitated by transmitting constant-amplitude pilot information with the other information. The amount of attenuation of the pilot information at the receiver is detected and used to control the amount by which received information is amplified. In this way the deleterious effects of free-space optical attenuation are substantially eliminated. The pilot information may be transmitted either via its own separate light frequency or wavelength or as a, distinguishable part of a larger quantity of information that is used to modulate one light frequency or wavelength.
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 February 12, 1998 and granted January 29, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 12, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 12, 2020.
- 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.