Fig. 1. Schematic diagram of SOI structure

Fig. 2. Schematic diagram and SEM image of the end-face alignment process of InP-based photonic integration of active and passive structures. (a) Active thin film growth and structure etching on InP；(b) passive layer regrowth and grating patterning；(c) common top cladding growth；(d) SEM image

Fig. 3. InP optical waveguide resonator^[17]. (a) InP optical waveguide resonant cavity structure; (b) low loss InGaAsP/InP ridge waveguide; (c) light field distribution at the tapered input; (d) light field distribution at tapered output

Fig. 4. Integrated optical gyroscope structural unit

Fig. 5. Monolithic integrated gyro resonator cavity structure^[21-22]

Fig. 6. Two structural forms of resonant cavity. (a) Double runway resonant cavity structure^[23]；(b) resonant cavity structure with loss compensation^[24]

Fig. 7. Gyroscope system composed of double resonant cavities^[25]. (a) System structure diagram；(b) architecture of SiO₂ dual-resonator

Fig. 8. Sketch map of transmissive resonator optic gyro based on silica-on-silicon waveguide^[26]

Fig. 9. Configuration of triple-ring resonator configuration^[28]

Fig. 10. Configuration of multi-ring resonant cavity^[29]. (a) Three-dimensional model; (b) top view

Fig. 11. Schematic diagram of integrated optical structure based on two-dimensional photonic crystal^[36]

Fig. 12. Micro-ring resonant cavity structure based on one-dimensional photonic crystal^[37]

Fig. 13. Schematic diagram of multi-turn optical waveguide ring resonator^[38]

Fig. 14. Schematic diagram of multi-turn optical waveguide resonator structure and gyroscope system structure^[39]

Fig. 15. Schematic diagram of resonant cavity of mode-assisted gyroscope^[40]. (a) Sensing element; (b) reference sensing element

Fig. 16. Resonant cavity with reciprocal sensitivity enhancement^[41]. (a) Structure chart; (b) schematic diagram of alternating light path

Fig. 17. Design scheme of optical gyroscope based on a multi-gap surface plasmon waveguide^[42]. (a) Structure chart; (b) cross section of multi-gap optical waveguide ring resonator

Fig. 18. Configuration of resonant cavity structure combined with MZI

Fig. 19. Schematic diagram of track-type ultrahigh-Q microcavity^[47]. (a) Three-dimensional view;(b) top view