Toroidal Dipole Excitation in Metamaterial Perfect Absorber Consisting of Dielectric Nanodisks Quadrumer Clusters and Spacer on Metal Substrate

We proposed an infrared narrowband metamaterial perfect absorber (MPA) which is induced by toroidal dipole resonance in a dielectric-metal hybrid system. The MPA composed of amorphous-silicon (a-Si) nanodisk quadrumer clusters, dielectric spacer, and Au substrate, where the spacer inserted between Si disk substrate. Near field distribution multipole decomposition far-field, scattering powers show that mode formed opposite phase magnetic dipoles neighboring nanodisks. effects geometric material parameters on absorption characteristics were explored. sensing performance was also evaluated. has potential applications air applications. Since nanodisks retains C4v symmetry, band polarization independent. Furthermore, quality factor higher than all-metal absorbers, thanks to low loss feature resonator.