(a) Schematic illustration of the metal-dielectric hybrid MS. (b) Front view of a single unit cell, with a unit cell period of a = 98 μm, Si pillar height h = 48 μm, SiO₂ spacer layer thickness e = 7 μm, Ag layer thickness l = 25 μm, central cylinder diameter d = 50 μm, and SiO₂ substrate thickness w = 170 μm. (c) Simulated two lowest-frequency TE-like band structure of the MS. The inset showing the electric field distribution (normE) of BIC mode at the Γ point. (d) Simulated radiation Q factors for the TE₁ and TE₂ bands in momentum space. The orange and green line represent fitted Q factor curve of the TE₁ and the TE₂ band, respectively.