Self-deflecting plasmonic lattice solitons and sur-face modes in chirped plasmonic arrays

TL;DR

This paper demonstrates that chirped plasmonic arrays with nonlinear focusing can support self-deflecting subwavelength lattice solitons and surface modes, with controllable trajectories and angles.

Contribution

It introduces the concept of self-deflecting plasmonic lattice solitons in chirped arrays and explores their properties and controllability.

Findings

Self-deflecting subwavelength solitons can be supported in chirped arrays.

Deflection angles are controllable via array chirp.

Surface modes exist at array boundaries even without nonlinearity.

Abstract

We show that chirped metal-dielectric waveguide arrays with focusing cubic nonlinearity can support plasmonic lattice solitons that undergo self-deflection in the transverse plane. Such lattice solitons are deeply-subwavelength self-sustained excitations, although they cover several periods of the array. Upon propagation,the excitations accelerate in the transverse plane and follow trajectories curved in the direction in which the separation between neighboring metallic layers decreases, a phenomenon that yields considerable deflection angles. The deflection angle can be controlled by varying the array chirp. We also reveal the existence of surface modes at the boundary of truncated plasmonic chirped arraythat form even in the absence of nonlinearity.