Abstract

The extreme effects of left-handed metamaterials on the electromagnetic fields, as e.g. amplification of evanescent waves, negative refraction, or even cloaking, have attracted a huge interest in scientific [1] and public media. However, as known from the Kramers-Kronig-relations, such deviations from the vacuum properties can only be achieved at the price of strong dispersion. Besides the fundamental problem posed by the loss of the metal components in the optical spectrum, the control of these inherent dispersive properties will be crucial for practical application of metamaterials. This is particularly true since in left-handed metamaterials two strongly dispersive effects have to be matched, one for the electric and one for the magnetic response. Moreover the realization of metamaterials for optical frequencies poses a great challenge on the existing nanotechnologies by itself. Hence the combination of strong dispersion caused by two independent resonant unit elements and the technological problems makes it difficult to realize metamaterials with reproducible parameters as would be required for any real application.

© 2007 IEEE