Circular dichroism in planar nonchiral plasmonic metamaterials

Abstract

It is shown theoretically that a nonchiral, two-dimensional array of metallic spheres exhibits optical activity as manifested in calculations of circular dichroism. The metallic spheres occupy the sites of a rectangular lattice and for off-normal incidence they show a strong circular-dichroism effect around the surface plasmon frequencies. The optical activity is a result of the rectangular symmetry of the lattice which gives rise to different polarizations modes of the crystal along the two orthogonal primitive lattice vectors. These two polarization modes result in a net polar vector, which forms a chiral triad with the wavevector and the vector normal to the plane of spheres. The formation of this chiral triad is responsible for the observed circular dichroism, although the structure itself is intrinsically nonchiral.

7 pages, 4 figures, to appear in Optics Letters

References in corpus (4)

• 3D-Chiral Metamaterial Showing Artificial Magnetic Response and Negative Refraction
• Giant gyrotropy due to electromagnetic coupling
• Optical Activity of Planar Achiral Metamaterials
• Plane waves with negative phase velocity in Faraday chiral mediums

Cited by in corpus (5)

• Chiral metamaterials: retrieval of the effective parameters with and without substrate
• Faraday Rotation and Circular Dichroism Spectra of Gold and Silver Nanoparticle Aggregates
• Self-similar plasmonic nanolenses: mesoscopic ensemble averaging and chiral light-matter interactions
• Capsize of polarization in dilute photonic crystals
• Kirigami-based Flexible Metasurface with Reconfigurable Intrinsic Chirality from Zero to Near-unity