Superscattering, Superabsorption, and Nonreciprocity in Nonlinear Antennas

TL;DR

This paper introduces tunable nonlinear antennas using epsilon-near-zero materials that enable dynamic control of scattering, absorption, and nonreciprocal radiation patterns for advanced optical applications.

Contribution

It presents a novel design of nonlinear antennas with tunable scattering and absorption, and demonstrates nonreciprocal radiation patterns enabled by epsilon-near-zero materials.

Findings

Antennas can switch between superscattering and superabsorption states.

Nonreciprocal radiation patterns are achieved through nonlinear effects.

Laser intensity controls the antenna's emission directionality.

Abstract

We propose tunable nonlinear antennas based on an epsilon-near-zero material with a large optical nonlinearity. We show that the absorption and scattering cross sections of the antennas can be controlled dynamically from a nearly superscatterer to a nearly superabsorber by changing the intensity of the laser beam. Moreover, we demonstrate that a hybrid nonlinear antenna, composed of epsilon-near-zero and high-index dielectric materials, exhibits nonreciprocal radiation patterns because of broken spatial inversion symmetry and large optical nonlinearity of the epsilon-near-zero material. By changing the intensity of the laser, the radiation pattern of the antenna can be tuned between a bidirectional and a unidirectional emission known as a Huygens source. Our study provides a novel approach toward ultrafast dynamical control of metamaterials, for applications such as beam steering and optical limiting.