Manipulating reflection-type all-dielectric non-local metasurfaces via the parity of a particle number

The parity of a particle number is a new degree of freedom for manipulating metasurface, while its influence on non-local metasurfaces remains an unresolved and intriguing question. We propose a metasurface consisting of periodically arranged infinite-long cylinders made from multiple layers of SiO₂ and WS₂. The cylinder exhibits strong backward scattering due to the overlapping magnetic dipole and electric quadrupole resonances. Without non-local coupling in unit cells, the infinite-size metasurface manifests high reflection across all instances. However, with non-local coupling in supercells, parity-dependent reflectivity diverges, exhibiting either increased logarithmic or decreased exponential behavior, with significant distinctions at small particle numbers. Interestingly, equal magnitude reflection and transmission reversals are achievable through alternation between adjacent odd and even particle numbers. The finite-size non-local metasurfaces behave similarly to the infinite-size counterparts, yet high reflection disappears at small particle numbers due to energy leakage. Essentially, high reflection arises from strong backward scattering and effective suppression of lateral multiple scatterings. Our work aids in the actual metasurface design and sheds new light on photonic integrated circuits and on-chip optical communication.