Sensitivity analysis and comparison of broadband source-driven resonant fiber-optic gyroscopes

This paper presents a comparative analysis of the rotation sensitivities of broadband source-driven resonant fiber-optic gyroscopes (RFOGs), utilizing transmissive and reflective fiber-optic ring resonators (FRRs) as the rotation-rate sensing elements, respectively. A broadband source-driven RFOG with a transmissive FRR works so well; however, the utilization of a reflective FRR results in a discernible reduction in gyroscope performance. This discrepancy can be attributed to the fact that in the former configuration, the entirety of the detected power originates from the circulating beams within the cavity, which is the beam that contributes to the Sagnac effect. In contrast, in the reflective FRR-based system, in addition to the circulating beams, a significant portion of the non-circulating light, which does not contribute to the Sagnac effect, is also detected by the photodetector. This results in a significantly reduced variation in the relative detected optical power induced by rotation, in comparison to the transmissive FRR-based system. Finally, two broadband source-driven RFOGs have been constructed and compared, using a transmissive FRR and a reflective FRR, respectively, as the rotation-rate sensing element. The test results demonstrate that the transmissive FRR-based system exhibits a superior angular random walk (ARW) of 0.003^∘/h^1/2 and a superior bias stability of 0.02°/h, whereas the reflective FRR-based system is limited to an ARW of 2.28^∘/h^1/2 and a bias stability of 14.54°/h. The discrepancies between the two are as much as factors of 760 and 720, which serves to reinforce the conclusion that the transmissive FRR is the preferred option for broadband source-driven RFOG.