Research On The Optical Path Optimization Of Resonant Fiber Optic Gyroscope

Resonator fiber optic gyro(RFOG)is a high accuracy inertial rotation sensor based on the Sagnac effect.For the Sagnac effect is very weak,the optical noises and structure of RFOG shows its great significance in performance of RFOG.Just for this reason,suppression of noises is a very critical step for a high accuracy RFOG.Firstly,the output characteristics of the Fiber Ring Resonator(FRR)are analyzed theoretically,then the model of relationship between the output intensity and the resonant frequency difference is obtained.The influence of various parameters of FRR on the output resonance curve is obtained through the analysis of the model.Then the signal processing of RFOG is briefly introduced.The related noises of RFOG was introduced,and the influence of each device on the system was briefly analyzed.The backscattering noise are tested and the threshold of stimulated Brillouin scattering in FRR is obtained.Different frequency modulation is applied to two optical signals,and the half-wave voltage of the phase modulator is tested.The backscattering noise is suppressed by means of carrier suppression.As the polarization noise suppression,using the method of twin 90° polarization axis rotated spices,then polarization transmission characteristics of this FRR are analyzed in theory,and compared with a single0 ° FRR from the polarization transmission characteristics.The temperature stability of the two FRR was tested experimentally.Twin 90 ° solution greatly improved the temperature stability,effectively restrain the polarization fluctuation noise.In order to further suppress the polarization noise,this dissertation adopts the single polarization fiber(SPF)to constitute the resonator and its temperature stability was tested.The experimental results show that in 20 ? ~ 60 ? temperature range is always only one polarization.This phenomenon indicates that this structure greatly improves the temperature stability of FRR and the polarization noise is effectively suppressed.In order to facilitate data processing and analysis,some test modules based on Labview is established.The output performance of gyro is analyzed.The noise of gyro output is obtained through the analysis method of Allan variance.