Patent ID: 7187448
Filing Date: 2007-03-06
Classification: G01C

Abstract:
1. A fiber-optic gyrometer, comprising: a Sagnac interferometer using two light waves propagating in opposite directions in an interferometer loop; a photodetector which delivers through an adaptor an electrical signal Ud representing the light intensity of the interference between the two light waves; phase modulator means for optically phase-shifting the light waves controlled by a square-wave modulation signal Um suitable for controlling an optical phase variation at a frequency FO substantially equal to 1/(2t an analog-digital converter at the output of said differential amplifier; and an adder/subtractor for accumulating the digital values successively provided by the analog-digital converter, said adder/subtractor providing a content representing a parameter of the rotation measurement of the gyrometer; means for inverting the phase of the clock at a frequency f, which is very much less than the frequency FO, so as to alternate the sense of the difference of samples at the output of the differential amplifier at the frequency f, the adder/subtractor being also controlled by the frequency f so that the adder/subtractor works alternately in adder or in subtractor.