Labyrinth-based left-handed metamaterials and subwavelength focusing of electromagnetic waves

摘要

We propose and demonstrate a new labyrinth based metamaterial structure that solves two major problems related to the split-ring resonator based structures. One of the problems related to the split-ring resonator structure is the bianisotropy, and the other problem is the electric coupling to the magnetic resonance of the split-ring resonator structure. These two problems introduce difficulties in obtaining isotropic left-handed metamaterial mediums. The new structure that we propose here solves both of these problems. We further show that in addition to the magnetic resonance, when combined with a suitable wire medium, the structure that we propose exhibits left-handed transmission band. A two-dimensional metamaterial based on the labyrinth structure is used to study imaging of a point source. Our experimental results show that it is possible to image the point source with half widths as small as λ/4 by using the labyrinth based metamaterial.