Non-reciprocal biasing for performance enhancement of the resonant fiber gyroscope with ‘Reflector’ using In-line Faraday rotators: Design, analysis and characterization

Abstract

Abstract Resonant fiber optic gyroscopes use highly expensive narrow linewidth lasers and complex lock-in detection methods since they measure changes in the beat frequency due to angular rotations. In our recent work, a novel resonant gyroscope with an embedded “reflector” was proposed along with a proof-of-principle demonstration. Our resonant gyroscope unconventionally utilizes the changes in optical intensity to measure angular velocity. In this work, a novel method of providing nonreciprocal bias has been designed and implemented using fiber pigtailed Faraday rotators to increase the gyroscope’s sensitivity. We have also created an in-line reflector within the resonator using thin film deposition, in order to stabilize and enhance the reflectance. Unlike earlier, we now use standard single mode fibers and a custom designed, feedback stabilized polarization controller to obtain a bias stability of 10.8 deg/h. Our all-fiber configuration shows enhanced performance and a shot noise limited sensitivity of 0.2 deg/h, indicating the potential for tactical grade performance (0.1–30 deg/h) at much reduced costs. The gyroscope’s performance in terms of sensitivity to Kerr nonlinear effects, ambient thermal changes and backscattering have also been analyzed and discussed in detail.