Fig. 1. Inline rectangular block disk resonator structure. (a) Schematic of three-dimensional structure; (b) schematic of XY two-dimensional structure

Fig. 2. Two kinds of disk resonator filters with or without embedded rectangular metal block. (a) Transmission spectra; electric field energy density distribution at (b) 480 nm and (c) 630 nm resonant wavelengths

Fig. 3. (a) Relationship between transmittance and resonance wavelength of embedded rectangular metal disk structure with different vertical widths h; (b) relationship between resonance wavelength and length h

Fig. 4. (a) Relationship between transmittance and resonance wavelength of embedded rectangular metal disk structure with different lateral widths S; (b) relationship between resonance wavelength and length S

Fig. 5. (a) Relationship between transmittance and resonance wavelength of embedded rectangular metal disk structure with different coupling distances d; (b) relationship between resonance wavelength and coupling distance d

Fig. 6. (a) Schematic of dual-channel wavelength division multiplexer based on embedded metal block filter; (b) transmission spectrum of tunable multi-channel wavelength demultiplexer; electric field intensity distribution of tunable multi-channel wavelength demultiplexer at (c) λ=556 nm, (d) λ=741 nm

Fig. 7. (a) Structural diagram of three-channel wavelength division multiplexer based on embedded metal block filter; (b) transmission spectrum of tunable multi-channel wavelength demultiplexer; electric field intensity distribution of tunable multi-channel wavelength demultiplexer at (c) λ=558 nm, (d) λ=748 nm, (e) λ=936 nm