Fig. 1. Structural diagram of slot-type feedback-coupled waveguide microring resonator. (a) Top view of structure; (b) slot waveguide structure; (c) structural stereogram

Fig. 2. Structural diagram of feedback-coupled waveguide microring resonator

Fig. 3. Influences of waveguide parameters on performance. (a) Effect of waveguide width on loss; (b) effect of slot width on loss

Fig. 4. Mode field distributions inside the waveguide. (a) Rectangular waveguide; (b) slot waveguide

Fig. 5. Output spectrum of microring resonator

Fig. 6. Output spectrum of FCW structure with feedback waveguide length of 2πR

Fig. 7. Output spectrum of FCW structure with feedback waveguide length of 3πR

Fig. 8. Output spectra of both FCW and traditional microring resonators

Fig. 9. Output powers of FCW and traditional microring resonators

Fig. 10. Effect of gap on output spectrum