Thales

Centre National De La Recherche Scientifique

Ecole Normale Superieure De Cachan

Ecole Normale Superieure Paris-saclay

Fabien Bretenaker

Gilles Feugnet

Sylvain Schwartz

Alfredo De Rossi

Arnaud Brignon

Sylvain Combrie

Maxime Descampeaux

Aranud Brignon

A passive resonant optical gyroscope comprising a cavity and operating with three frequencies comprises: a first injecting laser to inject a first optical beam into the cavity in a first direction; a second injecting laser to inject a second optical beam into the cavity in an opposite direction; a third injecting laser to inject a third optical beam into the cavity in one of the aforementioned directions, one laser amongst the injecting lasers having a master frequency, the two other injecting lasers, called the first and second slave lasers, respectively having a first slave frequency and a second slave frequency; a master servocontrol device; a first servocontrol stage comprising first and second slave devices; and a second servocontrol stage comprising first and second optical phase-locking devices respectively comprising a first and second slave oscillator to generate a first radiofrequency offset signal and a second radiofrequency offset signal.

Compact three-frequency resonant optical gyroscope

The general field of the invention is that of passive resonator gyros comprising an injection laser emitting an initial optical beam at a first frequency and a fiber optic cavity. The gyro according to the invention operates with three optical beams at three different optical frequencies. A first beam is injected in a first direction of rotation, the second and the third beam are injected in the contrary direction. The gyro includes three slaving devices maintaining each optical frequency at a specific mode of resonance of the cavity. The gyro includes means for measuring the frequency differences existing between the different frequencies. Combined together, these differences are representative of the length of the cavity and the angular rotational velocity of the cavity along an axis perpendicular to its plane.

Optical passive resonator gyro with three beams

Growing community of inventors

Velizy Villacoublay, France

Fabien Bretenaker