Frequency referencing system and method
CA 1251831 A · Owner: British Telecommunications Public Limited Company · Inventors: Hill, Godfrey R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system and method of referencing frequencies of radiation from a plurality of sources, for example lasers (1,2) includes a filter element (11), such as a Fabry-Perot etalon, onto which the radiation is incident. The filter element has a replicated set of passbands spaced apart in frequency. Detection means (12,13) detects radiation passing through the filter element (11) and provides corresponding output signals. Control means (16-18, 3, 4) is responsive to the output signals from the detection means (12,13) to control the sources (1,2) so that the radiation transmitted through the filter element (11) is maintained substantially constant. The bandwidths of the radiation are small compared …
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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 March 28, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 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.