Fig. 1. Structure diagram of Fano resonator based on microring cavity-assisted interference

Fig. 2. Transmission intensities of through and drop ports of microring (a=0.9978, k=0.25,R=10 μm)

Fig. 3. Transmission spectra of resonant interferometer under different phase differences. (a) 0-π; (b) π-2π

Fig. 4. Transmission spectra under different phase differences. (a) Transmission spectra when phase difference is (2n+1)π; (b) transmission spectra when phase difference is 2nπ

Fig. 5. Fano coupling line type spectra under different loss and coupling coefficients. (a) k=0.25; (b) a=0.9978

Fig. 6. Variance of wavelength at valley point with phase difference φ (0-π)

Fig. 7. Contours of slope S of spectra at resonance point (θ=2π) with respect to loss coefficient a and coupling coefficient k

Fig. 8. Contours of slope S of spectra at resonance point (θ=4π) with respect to loss coefficient a and coupling coefficient k

Fig. 9. t and φ values required to achieve a complete extinction state

Fig. 10. 2D contours of extinction ratios with different k and a under different φ

Fig. 11. 2D contours of extinction ratios under different phase differences. (a) Phase difference is π/2; (b) phase difference is 3π/2

Fig. 12. Schematic diagram of waveguide structure profile used in experiment (ring represents microring, bus represents straight waveguide, and g represents gap between two waveguides)

Fig. 13. Light field profile |E| of quasi fundamental TE mode of SOI waveguide (n_eff=2.363167)

Fig. 14. Relationship between coupling coefficient k and waveguide gap g in coupling region

Fig. 15. Optical microscope picture of fabricated device

Fig. 16. Spectra obtained from experiments. (a) Microring resonance and Fano resonance; (b) φ=55°; (c) φ=80°; (d) φ=50°; (e) φ=115°; (f) φ=40° (k=0.242, a=0.995, blue lines are experimental data, and gray lines are simulation data)

Fig. 17. SEM images of fabricated device. (a) Whole microring; (b) coupling region