Unlocking the full potential of wave-matter nonlinear coupling in the epsilon-near-zero regime

TL;DR

This paper demonstrates that epsilon-near-zero metamaterials enable significant nonlinear wave-matter interactions in thin structures, allowing dramatic pulse transformations without field enhancement, opening new avenues for compact nonlinear optical devices.

Contribution

Theoretical proof that standard nonlinearity can be exploited in epsilon-near-zero materials to achieve strong nonlinear effects in ultra-thin slabs without field enhancement.

Findings

Thin epsilon-near-zero slabs induce dramatic nonlinear pulse transformations.

Non-resonant nonlinear coupling occurs without field enhancement.

Potential for ultra-compact nonlinear optical devices.

Abstract

In recent years, unconventional metamaterial properties have triggered a revolution of electromagnetic research which has unveiled novel scenarios of wave-matter interaction. A very small dielectric permittivity is a leading example of such unusual features, since it produces an exotic static-like regime where the electromagnetic field is spatially slowly-varying over a physically large region. The so-called epsilon-near-zero metamaterials thus offer an ideal platform where to manipulate the inner details of the "stretched" field. Here we theoretically prove that a standard nonlinearity is able to operate such a manipulation to the point that even a thin slab produces a dramatic nonlinear pulse transformation, if the dielectric permittivity is very small within the field bandwidth. The predicted non-resonant releasing of full nonlinear coupling produced by the epsilon-near-zero condition does not resort to any field enhancement mechanisms and opens novel routes to exploiting matter nonlinearity for steering the radiation by means of ultra-compact structures.