Bulk photonic metamaterial with hyperbolic dispersion

TL;DR

This paper reports the creation of a large, three-dimensional bulk photonic metamaterial with hyperbolic dispersion using silver nanowire networks, enabling advanced optical applications like sub-diffraction imaging.

Contribution

It introduces the thickest self-standing bulk hyperbolic metamaterial with anisotropic dielectric properties, expanding the physical size and potential applications of such materials.

Findings

Demonstrated a 1cm x 1cm x 51mm bulk metamaterial

Achieved hyperbolic dispersion with anisotropic dielectric constants

Observed beam shifts consistent with anisotropic refraction

Abstract

In this work, we demonstrate a self-standing bulk three-dimensional metamaterial based on the network of silver nanowires in an alumina membrane. This constitutes an anisotropic effective medium with hyperbolic dispersion, which can be used in sub-diffraction imaging or optical cloaks. Highly anisotropic dielectric constants of the material range from positive to negative, and the transmitted laser beam shifts both toward the normal to the surface, as in regular dielectrics, and off the normal, as in anisotropic dielectrics with the refraction index smaller than one. The designed photonic metamaterial is the thickest reported in the literature, both in terms of its physical size 1cm x 1cm x 51 mm, and the number of vacuum wavelengths, N=61 at l=0.84 mm.