Recent disclosures on subwavelength plasmonic crystals, like the potential excitation of a pair of coexisting wave-fields with opposite refraction, only can be understood by considering two dispersion branches with completely different features that characterize the metamaterial. One branch gives elliptic-like dispersion and the other provides hyperbolic-like dispersion. However the effective medium approximation, also known as Rytov approximation, is not consistent with both curves simultaneously. We follow an approach leading to a single curve that allows a complete description of both diffraction behaviors concurrently. Importantly only two parameters of the closed curve, together with the lattice period, fulfill such a complete picture. In addition, our semi-analytical approach may include more general situations straightforwardly.

Date Published: 1 May 2012
PDF: 7 pages
Proc. SPIE 8423, Metamaterials VII, 84231Z (1 May 2012); doi: 10.1117/12.922118

Published in SPIE Proceedings Vol. 8423:
Metamaterials VII
Allan D. Boardman; Nigel P. Johnson; Richard W. Ziolkowski, Editor(s)