Open-loop output and scale factor stability in a fiber-optic gyroscope

An all-fiber open-loop, fiber-optic interferometric gyro with polarization-preserving fiber with 14-dB insertion loss and 20-dB polarization extinction is described. The random drift coefficient is 3.2*10/sup -40// square root h for a 1-km coil length on a 16-cm radius. Bias drift is within 0.03 degrees /h over three days. Source coherence effects and optical feedback are shown to result in additional terms in the demodulated output, which can be corrected for. A procedure for obtaining scale-factor coefficients is described. With modeling for temperature and source drive current, these coefficients are measured to be stable within 32 p.p.m. over 12 days.<
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