Interferometer gyroscope with electro-optical modulation and reduced reset frequency

A gyroscope comprising:

• a coiled dielectric waveguide constituting a ring and having two ends;
• a source of electromagnetic waves provided with a splitter connected to said ends of the dielectric waveguide for sending two contra-rotating waves from said source into said ring;
• an interference detector connected to receive said contra-rotating wave after they have circulated in said ring;
• first electro-optical means optically coupled with said dielectric waveguide and controlled to impart a periodic alternating and symmetrical phase modulation to said electromagnetic waves at a period which is substantially twice the travel time of said electromagnetic waves in said ring, said first electrooptical means being located upstream from the ring for one of said contrarotating waves and downstream of said ring for the other contra-rotating waves;
• second electro-optical means located upstream from the ring for one of said contra-rotating waves and downstream of the ring of the other;
• a phase shift sawtooth generator connected to deliver voltage ramps of controllable slope and controllable polarity to said second electro-optical means;
• electronic means connected to said interference detector and constructed to be responsive to a phase difference between said contra-rotating waves received by said interference detector;
• means for reversing said polarity of said ramps whenever said phase difference exceeds +.pi./2 or is beyond -.pi./2;
• and
• means for algebrically summing said changes of polarity of said ramps.