Optically isotropic negative index of refraction metamaterial

Abstract

We report a metamaterial with optically isotropic negative refraction index, n, and small loss factor, k = |Im (n)/Re (n)| ≤ 0.4, that occurs near the visible/UV line. The metamaterial presented consists of two media. One medium (randomly distributed gold spherical nanoparticles with Drude‐like permittivity, in free space) ensures negative permittivity, and another medium (spherical SiC nanoparticles) ensures negative permeability via the Mie resonance within the same frequency range. We have found, self‐consistently, in the framework of both the effective medium approach and rigorous first‐principles based Finite Difference Time Domain (FDTD) simulations, that the metamaterial exhibits negative refraction index behavior. This result stands for both the random distribution of the SiC particles, and the regular simple‐cubic lattice of the same particles. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

High symmetry versus optical isotropy of a negative-index metamaterial

“…To overcome this obstacle various approaches for obtaining isotropic MMs have been put forward. [8][9][10][11][12][13][14] A systematic approach to design an isotropic magnetically active MM was proposed by Baena et al 15 The first step is to choose a highly symmetric MM. Such MM is constructed based on a cubic unit cell arranged at a cubic lattice.…”

Lewin's homogenization formula revisited for nanocomposite materials

“…Noting that homogenization formulas can be applicable to composite materials containing nanosized inclusions, in this letter crucial limitations of Lewin's formula are identified which have not been respected in recent studies [6][7][8][9][10].…”

“…Lewin's formula has recently attracted attention in the context of HCMs which support negative-phase-velocity propagation of plane waves and can therefore refract negatively [6][7][8][9][10]. The constituents of the composite material considered by Lewin are: (i) an isotropic dielectric-magnetic host material with relative permittivity 1 and relative permeability µ 1 ; and (ii) an isotropic dielectric-magnetic inclusion material with relative permittivity 2 and relative permeability µ 2 .…”

“…The constituents of the composite material considered by Lewin are: (i) an isotropic dielectric-magnetic host material with relative permittivity 1 and relative permeability µ 1 ; and (ii) an isotropic dielectric-magnetic inclusion material with relative permittivity 2 and relative permeability µ 2 . The inclusion material has the form of spherical particles, each of radius a, arranged on a cubic lattice with f denoting the volume fraction of the inclusion material; Lewin's homogenization formula has also been applied to composites with randomly distributed inclusions [9]. The dimensionless parameter…”

Coupled plasmon-exciton induced transparency and slow light in plexcitonic metamaterials

“…However, the size of the inclusions can be large enough to be described classically with some proper dielectric functions and polarizabilities. Classical approaches and numerical simulations of Maxwell's equations have been successfully used to model both the optical response of the constituent elements and the collective behavior of many metamaterial nanostructures, containing metallic and semiconductor inclusions [9][10][11].…”