The role of local field modes in calculating the effective optical properties of metamaterials

TL;DR

This paper emphasizes the significance of local field modes in determining the effective optical properties of metamaterials, introducing a corrected Maxwell-Garnett formula and analyzing surface plasmon effects through numerical simulations.

Contribution

It presents a modified Maxwell-Garnett approach incorporating local field effects and surface plasmons for more accurate effective medium predictions.

Findings

Corrected Maxwell-Garnett formula aligns better with full mode analysis

Surface plasmon polaritons significantly influence effective refractive index

Numerical simulations validate the importance of local field considerations

Abstract

This letter discusses the importance of the nature of local fields inside a unit cell of optical metamaterials in developing a valid effective medium theory. In particular, we apply the Meier-Wokaun procedure to derive a corrected version of the Maxwell-Garnett formula for the refractive index of a medium composed by metallic rods with subwavelength cross-section. We compare this result with the values obtained using the full mode analysis calculated via numerical simulations and analyze the impact of surface plasmon polaritons in adequately determining the effective refractive index of the medium.