On the Nonlocal Response of Multilayer Optical Metamaterials

Abstract

We provide a microscopic description of a three-dimensional infrared metamaterial composed of stacked arrays of gold cut wires buried in a dielectric host. We show with numerical and theoretical arguments that the response of this structure is intrinsically nonlocal and explain why this property makes it robust to fabrication errors such as misalignments between adjacent levels of cut wires. We then validate these claims by fabricating and characterizing experimental samples comprising up to four layers of cut wires. These results relax the fabrication tolerances of bulk optical metamaterials composed of strongly interacting layers and also imply that their effective parameters cannot be inferred from retrieval methods based on a purely local description of the permittivity and permeability.

Beyond local effective material properties for metamaterials

“…These additional boundary conditions for the materials considered here are beyond the scope of this contribution and will be discussed elsewhere 32 . In the context of nonlocal constitutive relations, comparable approaches were already employed to effectively homogenize metamaterials beyond their local regime [21][22][23][24][25][26][27][28] . However, very often they required a specific geometry for the metamaterial that motivated the formulation of specific constitutive relations.…”