Artificial Nonlinearity Generated from Electromagnetic Coupling Meta-molecule

TL;DR

This paper introduces an artificial optical nonlinearity mechanism using a metamaterial meta-molecule, driven by electromagnetic coupling, enabling customizable nonlinear responses for advanced optical applications.

Contribution

It presents a novel, purely artificial nonlinear mechanism based on electromagnetic interactions in a meta-molecule, expanding design possibilities beyond natural nonlinear materials.

Findings

Demonstrates second-order nonlinear behavior through numerical simulations.

Shows the mechanism is controlled by meta-molecule geometry.

Provides a new approach for designing nonlinear optical devices.

Abstract

A purely artificial mechanism for optical nonlinearity is proposed based on a metamaterial route. The mechanism is derived from classical electromagnetic interaction in a meta-molecule consisting of a cut-wire meta-atom nested within a split-ring meta-atom. Induced by the localized magnetic field in the split-ring meta-atom, the magnetic force drives an anharmonic oscillation of free electrons in the cut-wire meta-atom, generating an intrinsically nonlinear electromagnetic response. An explicit physical process of a second-order nonlinear behavior is adequately described, which is perfectly demonstrated with a series of numerical simulations. Instead of "borrowing" from natural nonlinear materials, this novel mechanism of optical nonlinearity is artificially dominated by the meta-molecule geometry and possesses unprecedented design freedom, offering fascinating possibilities to the research and application of nonlinear optics.