RESONATOR FIBER OPTIC GYROSCOPE EMPLOYING COMMON CAVITY LENGTH MODULATION ALONG WITH HIGH BANDWIDTH LASER STABILIZATION

摘要

A resonator fiber optic gyroscope comprises a master laser device that emits a reference optical signal, a first slave laser device that emits a clockwise optical signal, and a second slave laser device that emits a counter-clockwise optical signal. A resonator ring cavity is in communication with the master laser device and the slave laser devices. A sine wave generator is coupled to the resonator ring cavity and outputs a common cavity modulation frequency comprising in-phase and quadrature signals. A laser stabilization servo receives a clockwise reflection signal that includes the common cavity modulation frequency from the resonator ring cavity. A modulation stripper coupled to the servo receives the in-phase and quadrature signals, receives a net error signal from the servo, demodulates the net error signal at the common cavity modulation frequency, and transmits a stripper signal to the servo to remove the signal at the common cavity modulation frequency.

主权项

1. A resonator fiber optic gyroscope (RFOG), comprising:
a master laser assembly including a master laser device configured to emit a reference optical signal; a first slave laser assembly including a first slave laser device configured to emit a clockwise (CW) optical signal, the first slave laser device responsive to the reference optical signal through a CW optical phase lock loop; a second slave laser assembly including a second slave laser device configured to emit a first counter-clockwise (CCW) optical signal, the second slave laser device responsive to the reference optical signal through a first CCW optical phase lock loop; an optical resonator ring cavity in optical communication with the master laser device, the first slave laser device, and the second slave laser device; a sine wave generator operatively coupled to the resonator ring cavity and configured to output a common cavity modulation frequency comprising an in-phase (I) signal component and a quadrature (Q) signal component; a laser stabilization servo module configured to receive a CW reflection signal that includes the common cavity modulation frequency from the resonator ring cavity; a modulation stripper operatively coupled to the laser stabilization servo module, the modulation stripper configured to:
receive the I and Q signal components of the common cavity modulation frequency from the sine wave generator;receive a net error signal from the laser stabilization servo module;demodulate the net error signal at the common cavity modulation frequency; andtransmit a stripper signal to the laser stabilization servo module to remove the signal at the common cavity modulation frequency; and a resonance tracking electronics module operatively coupled to the resonator ring cavity and configured to output resonance tracking error signals to the first and second slave laser assemblies; wherein the laser stabilization servo module is configured to send a tuning signal to the master laser device as part of a feedback stabilization loop for the master laser device.