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Backscatter noise is a key limiting factor in the performance of resonant fiber optic gyroscopes. To enhance the accuracy of resonant fiber optic gyroscopes, a gyroscope system based on sideband locking technology is proposed. In this scheme, two tunable semiconductor lasers independently provide the clockwise and counterclockwise optical paths. An optical phase-locked loop is employed to achieve independent subharmonic phase locking of the two output lights, with their optical frequency difference equaling one free spectral range (FSR). By applying sinusoidal modulation at different frequencies to generate sidebands, the sideband locking technique is used to lock the first-order sidebands of the two lights to adjacent resonant frequencies. Through the filtering effect of the fiber ring resonator, the carrier intensity of the transmitted light and other sidebands are effectively suppressed. With this signal processing technique, the influence of two types of backscatter noise is completely eliminated, and the additional suppression of laser frequency noise is achieved. Experimental results show that, based on the Allan deviation, the bias instability of the gyroscope output is 1.42°/h. This method significantly improves the detection accuracy of the resonant fiber optic gyroscope under the same parameter precision or device performance requirements. [ABSTRACT FROM AUTHOR]

In the development of miniaturized optical gyroscopes, the resonant micro-optical gyroscope (RMOG) is the most representative sensor of new optical gyroscopes. However, in the manufacturing process of optical elements, the influence of backscattering and optical Kerr noise limits the performance of RMOG. A method of suppressing optical Kerr noise generated by the front end by compensating the optical power difference while suppressing the backscattering noise is introduced. In this method, we study the optimal strategy of double-phase modulation frequency to obtain the maximum spectral gap of clockwise and counterclockwise light, so as to suppress the error related to backscattered light. At the same time, the influence of Kerr noise on the optical path is reduced through the high-precision feedback loop of the intensity modulator. Based on Allan variance, the long-term deviation stability of RMOG reaches 0.98 deg/h. [ABSTRACT FROM AUTHOR]

A self-injection locking method for resonant micro-optical gyroscope (RMOG) is proposed. The resonator is used as the sensitive element of the gyroscope and the device of light compression locking. The fiber and waveguide ring resonator (WRR) are designed and fabricated, consecutively. Both of the resonators can narrow the linewidth by three orders of magnitude, and the phase noise and the relative intensity noise can be reduced to −120 and −150 dBc / Hz, respectively. By evaluating the locking effect, WRR is more suitable for optical locking of a resonant micro-optical gyroscope (RMOG) light source, and its theoretical locking accuracy can reach 6.02 deg/s. [ABSTRACT FROM AUTHOR]