Fig. 1. Working principle of MDM-WDM hybrid demultiplexer

Fig. 2. Theoretical model of WDM

Fig. 3. Transmission spectra of theoretical model. (a) Theoretical transmission spectra of each port; (b) local magnification of reflection spectrum

Fig. 4. Three-dimensional structural diagram of MDM-WDM hybrid demultiplexer

Fig. 5. Structural parameters and static field distribution of one-dimensional photonic crystal nanobeam cavity. (a) Structural diagram; (b) hole radius distribution in microcavity area; (c) static field distribution of resonant cavity mode

Fig. 6. Structural diagrams of WDM demultiplexer. (a) Three-dimensional; (b) two-dimensional

Fig. 7. Transmission spectra of WDM demultiplexer. (a) Transmission spectrum at each port; (b) enlarge views of transmission spectra

Fig. 8. Static field distributions of different incident light in WDM demultiplexing process. (a) 1570.0 nm; (b) 1573.2 nm

Fig. 9. Relationship between performance of WDM demultiplexer and Δr. (a) Insertion loss at each wavelength versus Δr; (b) channel crosstalk at each wavelength versus Δr

Fig. 10. Structural parameters and transmission spectra of MDM demultiplexer. (a) Effective refractive index map of nanowire waveguides; (b) three-dimensional structural diagram; (c) side view of three-dimensional structure; (d) transmission spectra; (e) different mode conversion diagrams

Fig. 11. Relationship between performance of MDM demultiplexer and L_c. (a) Insertion loss of each mode versus L_c; (b) channel crosstalk of each mode versus L_c

Fig. 12. Transmission spectra of ports O₃ and O₄ in demultiplexing process. (a) Hole is not fine-tuned; (b) hole is fine-tuned

Fig. 13. Transmission spectra of each mode in demultiplexing process. (a) TE₀; (b) TE₁

Fig. 14. Static field distribution in demultiplexing process. (a) TE₀ at 1570.0 nm; (b) TE₀ at 1573.2 nm; (c) TE₁ at 1570.0 nm; (d) TE₁ at 1573.2 nm