Negative refraction in nonlinear wave systems

TL;DR

This paper predicts and verifies negative refraction in nonlinear wave systems, showing it depends on physical conditions rather than special materials, with potential applications in various oscillatory media.

Contribution

It introduces the concept of negative refraction in nonlinear oscillatory systems, expanding the phenomenon beyond linear optics and demonstrating its feasibility through theoretical and numerical methods.

Findings

Negative refraction occurs in nonlinear systems under Hopf bifurcation.

It does not require left-handed materials, unlike in linear optics.

Feasibility shown via Ginzburg-Landau and reaction-diffusion models.

Abstract

People have been familiar with the phenomenon of wave refraction for several centuries. Recently, a novel type of refraction, i.e., negative refraction, where both incident and refractory lines locate on the same side of the normal line, has been predicted and realized in the context of linear optics in the presence of both right- and left-handed materials. In this work, we reveal, by theoretical prediction and numerical verification, negative refraction in nonlinear oscillatory systems. We demonstrate that unlike what happens in linear optics, negative refraction of nonlinear waves does not depend on the presence of the special left-handed material, but depends on suitable physical condition. Namely, this phenomenon can be observed in wide range of oscillatory media under the Hopf bifurcation condition. The complex Ginzburg-Landau equation and a chemical reaction-diffusion model are used to demonstrate the feasibility of this nonlinear negative refraction behavior in practice.