Anisotropic Metamaterial Optical Fibers

TL;DR

This paper explores the design and properties of anisotropic metamaterial optical fibers, which utilize structured nanopores filled with metals to support unique electromagnetic modes, expanding the capabilities of waveguides.

Contribution

It introduces a novel anisotropic metamaterial fiber structure with nanopores filled with plasmonic metals, supporting exotic modes not seen in traditional fibers.

Findings

Nanopores filled with metals increase electromagnetic anisotropy.

Anisotropic fibers support uncommon Bessel function modes.

Potential for new light-guiding applications.

Abstract

Internal physical structure can drastically modify the properties of waveguides: photonic crystal fibers are able to confine light inside a hollow air core by Bragg scattering from a periodic array of holes, while metamaterial loaded waveguides for microwaves can support propagation at frequencies well below cutoff. Anisotropic metamaterials assembled into cylindrically symmetric geometries constitute light-guiding structures that support new kinds of exotic modes. A microtube of anodized nanoporous alumina, with nanopores radially emanating from the inner wall to the outer surface, is a manifestation of such an anisotropic metamaterial optical fiber. The nanopores, when filled with a plasmonic metal such as silver or gold, greatly increase the electromagnetic anisotropy. The modal solutions in anisotropic circular waveguides can be uncommon Bessel functions with imaginary orders.