Three-Dimensional Nanotransmission Lines at Optical Frequencies: A Recipe for Broadband Negative-Refraction Optical Metamaterials

TL;DR

This paper designs a 3-D plasmonic nanotransmission line network that acts as a broadband negative-refraction optical metamaterial, with detailed analysis showing increased bandwidth and robustness at infrared and optical frequencies.

Contribution

It introduces a novel 3-D nanotransmission line approach for broadband negative refraction in optical metamaterials, including analytical modeling and design examples.

Findings

Increased bandwidth and robustness to losses demonstrated.

Full-wave analytical results support design feasibility.

Potential for sub-wavelength imaging applications.

Abstract

Here we apply the optical nanocircuit concepts to design and analyze in detail a three-dimensional (3-D) plasmonic nanotransmission line network that may act as a negative-refraction broadband metamaterial at infrared and optical frequencies. After discussing the heuristic concepts at the basis of our theory, we show full-wave analytical results of the expected behavior of such materials, which show increased bandwidth and relative robustness to losses. The possibility and constraints of getting a 3-D fully isotropic response is also explored and conditions for minimal losses and increased bandwidth are discussed. Full-wave analytical results for some design examples employing realistic plasmonic materials at infrared and optical frequencies are also presented, and a case of sub-wavelength imaging system using a slab of this material is numerically investigated.