Determining optical signal transit delay time in an optical interferometer
CA 2122906 C · Owner: Ferrar, Carl M. · Inventors: Ferrar, Carl M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a fiber optic gyroscope , (10) having a pair of light waves counter-propagating , in a fiber optic loop (44), a phase modulator (28), driven with a variable frequency and amplitude modulation , signal on a line (32) so as to any rotation , induced optical phase shift; and using the difference , between the drive frequency and the loop eigenfrequency, as a measure of rotation rate, is provided with a , calibration circuit (34) which determines the actual loop, eigenfrequency while in rotation. A modulation signal, is applied having an amplitude that causes the closed, loop output frequency to equal the loop eigenfrequency , independent of rotation rate. The amplitude is, fine tuned by …
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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
- Filed April 7, 1992 and granted March 27, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 7, 2014.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.