Bias Error Caused by the Faraday Effect in Fiber Optical Gyroscope With Double Sensitivity

We present an investigation of bias error caused by the Faraday effect in interferometric fiber optical gyroscopes (IFOGs) with double sensitivity. Jones matrix method is utilized to formulize the bias error in IFOGs with double sensitivity under the action of radial magnetic field. Theoretical results show that the bias error caused by the Faraday effect can be suppressed effectively in IFOGs with double sensitivity. Experiments with different lengths and twists of fiber coils are performed, and the experimental results support these theoretical predictions. For 490- and 1020-m polarization maintaining fiber coils, the maximum errors generated by a 1-mT radial magnetic field are 0.8°/h and 0.5°/h, respectively. This letter is promising for improving the bias stability of IFOGs.