Method for compensating the effect of temperature on the error of a fiber-optic gyroscope with a birefringence modulator

Subject of study. This study investigated a method for reducing the error of a fiber-optic gyroscope equipped with a birefringence modulator (BM) under temperature variations. Aim of study. The aim of this study was to develop and experimentally investigate a method for compensating the nonlinear influence of temperature on the error of a fiber-optic gyroscope with a BM. Method. The proposed method reduces the temperature-induced error of a fiber-optic gyroscope by increasing the optical-fiber length to values exceeding the depolarization length, which decreases the amplitude modulation of the signal caused by parasitic interference effects. Experiments were performed to evaluate the influence of temperature changes and the rate of those changes on the gyroscope error. Main results. The root-mean-square deviation of the signal decreased from 0.055 deg/h to 0.023 deg/h within the temperature range of 16–36°C and from 0.01 deg/h to 0.003 deg/h under stable-temperature conditions. The signal drift decreased from 0.33 deg/h to 0.13 deg/h over the same temperature range and from 0.055 deg/h to 0.019 deg/h under stable-temperature conditions. Segments showing the nonlinear dependence of the angular-rate signals on temperature disappeared. An additional time delay between wave trains with orthogonal polarization states was introduced to reduce the error of the fiber-optic gyroscope with a BM. Practical significance. The proposed method can be used to reduce the impact of temperature on the accuracy parameters of navigation systems.