Fig. 1. RFOG setup. ASE, amplified spontaneous emission; PD, photodetector; FPGA, field programmable gate array; MIOC, multifunction integrated-optics chip; FRR, fiber ring resonator; CW, clockwise; CCW, counterclockwise; AD, analog-to-digital; DA, digital-to-analog. Different from traditional IFOGs based on the minimal scheme, the long fiber coil is replaced with a high-finesse FRR. A photograph of the RFOG setup is also provided in Fig. 8 in Appendix A.

Fig. 2. (a) Simulation analysis and (b) experimental demonstration of Eq. (4). They are the outputs of the proposed white-light multibeam interferometry and are defined as the response curves of the proposed RFOG.

Fig. 3. Modulation signals and the corresponding PPD in different gyro states. VMIOC, voltage applied on the MIOC; Vπ, half-wave voltage; fmod, modulated frequency bias.

Fig. 4. (a) Demodulation process in the FPGA; (b) measured error signal versus fsag. LPF, low-pass filter.

Fig. 5. Test results of the RFOG. Gyro readout under sinusoidal rotation of (a) 10°/h, (b) 1°/h, and (c) 0°/h; (d) moving average of the static test data in (c) with a time window of 1000 s; (e) spectral power density of the results in (a)–(c); (f) Allan deviation of the static test data in (c).

Fig. 6. RIN of PPD and Pin. The working frequency of the RFOG is 21 kHz.

Fig. 7. Scheme of introducing equivalent Sagnac frequency via sawtooth modulation. (a) Modulation waveforms at two arms of the MIOC; (b) modulation process and scheme.

Fig. 8. Photograph of the RFOG system. PC, personal computer.