Optical Characteristics of Metasurfaces at Meta-Atom Anapole

Optical characteristics of square-latticed metasurfaces are analyzed by equations derived from a dipole-quadrupole system. For the metasurface composed Si nanospheres, meta-atoms maintain anapole single scatterer, which not affected lattice period. The far-field response thus can be engineered without significantly disturbing near-fields in meta-atoms. In addition, as exhibited with Ag/Si core-shell transmittance at also modulated and even nulled shifting magnetic dipole quadrupole resonances. small-period metasurface, near-field interaction adjacent manipulates resonance behavior, leading to significant modulation anapole.