Integrated photonics gyroscope with common intensity modulation

A photonics gyroscope, comprising:

• a laser device configured to emit an optical signal;
• a common intensity modulation unit configured to receive the optical signal from the laser device and produce an intensity modulated optical signal, wherein the intensity modulated optical signal is output from the common intensity modulation unit and split into a counter-clockwise (CCW) intensity modulated optical signal having a first power level, and a clockwise (CW) intensity modulated optical signal having a second power level;
• a first phase modulator optically coupled to the common intensity modulation unit, the first phase modulator configured to receive the CCW intensity modulated optical signal and produce a CCW phase modulated optical signal;
• a second phase modulator optically coupled to the common intensity modulation unit, the second phase modulator configured to receive the CW intensity modulated optical signal and produce a CW phase modulated optical signal;
• a first variable optical attenuator optically coupled to the first phase modulator, or optically coupled to the second phase modulator, the first variable optical attenuator configured to receive the CCW phase modulated optical signal or the CW phase modulated optical signal;
• an optical resonator in optical communication with the first variable optical attenuator, wherein the CCW phase modulated optical signal is optically coupled into the optical resonator and propagates in a CCW direction in the optical resonator, and the CW phase modulated optical signal is optically coupled into the optical resonator and propagates in a CW direction in the optical resonator;
• a first optical detector in optical communication with the optical resonator, and configured to receive the CCW phase modulated optical signal from the optical resonator;
• a second optical detector in optical communication with the optical resonator and configured to receive the CW phase modulated optical signal from the optical resonator;
• a CCW control loop operatively coupled between an output of the first optical detector and an input of the first phase modulator, the CCW control loop configured to lock the CCW phase modulated optical signal to a CCW resonance peak;
• a CW control loop operatively coupled between an output of the second optical detector and an input of the second phase modulator, the CW control loop configured to lock the CW phase modulated optical signal to a CW resonance peak;
• and
• a rate calculation unit configured to receive digital signals output from the CCW control loop and the CW control loop, the rate calculation unit operative to calculate a rotation rate signal for the photonics gyroscope;
• wherein the first variable optical attenuator is configured to receive a signal from a feedback loop to aid in adjusting the first variable optical attenuator to balance the power levels between the CCW and CW phase modulated optical signals to eliminate the rate signal at an intensity modulation frequency;
• wherein the feedback loop maintains the balance of the power levels between the CCW and CW phase modulated optical signals such that a Kerr effect bias error in the photonics gyroscope is reduced or eliminated;
• wherein the common intensity modulation unit, the phase modulators, the optical detectors, the variable optical attenuator, the control loops, and the rate calculation unit, are integrated on a single photonics chip with the optical resonator.