Negative refraction in plasmonic crystals of metallic nanoshells

Negative refraction in plasmonic crystals of metallic nanoshells: Publication year: 2011
Source: Metamaterials, In Press, Accepted Manuscript, Available online 26 August 2011
C., Tserkezis , N., Stefanou
We report on the optical response and, in particular, on the refractive properties of an fcccrystal of metallic nanoshells by means of full-electrodynamic layer-multiple-scattering simulations. Exact numerical calculations of the isofrequency surfaces reveal the existence of two frequency regions where negative refraction occurs. A thorough analysis of the photonic band structure, in conjunction with corresponding transmission diagrams, attributes this behavior to the excitation of collective modes, which stem from dipole particle-plasmon resonances, and shows that only in one of the two frequency regions negative refraction without birefringence can be obtained. In addition, we discuss the effect of absorptive losses, and...
Highlights: ► Negative refraction in photonic crystals of metallic nanoshells is demonstrated. ► Polarization-selective negative refraction occurs through plasmonic modes. ► Flat bands of slab modes that transfer evanescent waves without attenuation exist. ► Absorptive losses reduce propagation length to about ten lattice constants.