Patent ID: 8223341

Claim:
A fiber optic gyroscope comprising: a first laser source configured to produce a first laser beam having a first frequency; a second laser source configured to produce a second laser beam having a second frequency; a sensing resonator having a first input coupled to the first laser source and a second input coupled to the second laser source such that the first laser beam propagates through the sensing resonator in a first direction and the second laser beam propagates through the sensing resonator in a second direction; first resonance tracking electronics (RTE) configured to generate a first control signal that indicates when the first laser beam is off resonance; second resonance tracking electronics (RTE) configured to generate a second control signal that indicates when the second laser beam is off resonance; a first intensity modulator coupled between a first output of the sensing resonator and an input of the first resonance tracking electronics, the first intensity modulator configured to modulate the intensity of a signal from the first output of the sensing resonator at a first intensity modulation frequency such that the first resonance tracking electronics is able to discriminate between the signal from the first output of the sensing resonator and electronic noise, wherein the first intensity modulation frequency is different from a resonance tracking modulation frequency of the first RTE; and a second intensity modulator coupled between a second output of the sensing resonator and an input of the second resonance tracking electronics, the second intensity modulator configured to modulate the intensity of a signal from the second output of the sensing resonator at a second intensity modulation frequency such that the second resonance tracking electronics is able to discriminate between the signal from the second output of the sensing resonator and electronic noise, wherein the second intensity modulation frequency is different from a resonance tracking modulation frequency of the second RTE.