Thresholdless surface solitons

TL;DR

This paper introduces a new class of nonlinear surface waves called thresholdless surface solitons that do not require a minimum energy to excite and can extend into media on both sides of an interface, with potential stability.

Contribution

It demonstrates the existence and stability of thresholdless surface solitons in periodically modulated media, expanding understanding of nonlinear surface wave phenomena.

Findings

Thresholdless surface solitons can be excited without a threshold energy.

These solitons extend into both media at the interface.

They can be stable across their entire existence domain.

Abstract

We report on the existence of nonlinear surface waves which, on the one hand, do not require the threshold energy flow for their excitation, and, on the other hand, extend into media at both sides of the interface at low powers, i.e. can not be reduced to the conventional Tamm states. Such waves can be excited if the refractive index in at least one of the materials forming the interface is periodically modulated, with properly selected modulation depth and frequency. Thresholdless surface solitons can be stable in the entire existence domain.