We present a negative refractive index medium (NRIM) operating at multiple-angle incidences by expanding a conventional planar metamaterial to a three-dimensional (3D) structure. The proposed 3D NRIM is comprised of semi-spherical metal shells and planar plamonic wires, thus giving rise to negative magnetic permeability and negative electric permittivity, respectively. Our results show that reflectance (transmittance) peaks slightly which locate the region of negative refraction index are insensitive to the incident angles from 0° to 45° and the polarization of the excitation wave at a certain range of frequencies. Such pseudo-isotropic NRIM may be exploited for superlens and antenna applications.

Date Published: 10 September 2010
PDF: 8 pages
Proc. SPIE 7754, Metamaterials: Fundamentals and Applications III, 77541U (10 September 2010); doi: 10.1117/12.862500

Published in SPIE Proceedings Vol. 7754:
Metamaterials: Fundamentals and Applications III
Allan D. Boardman; Nader Engheta; Mikhail A. Noginov; Nikolay I. Zheludev, Editor(s)