Space-Time Surface Plasmon Polaritons: A New Propagation-Invariant Surface Wave Packet
Abstract
We introduce the unique class of propagation-invariant surface plasmon polaritons (SPPs) representing pulsed surface wave packets propagating along unpatterned metal-dielectric interfaces and are localized in all dimensions - with potentially subwavelength transverse spatial widths. The characteristic features of such linear diffraction-free, dispersion-free `plasmonic bullets' stem from tight spatio-temporal correlations incorporated into the SPP spectral support domain, and we thus call them `space-time' SPPs. We show that the group velocity of space-time SPP wave packets can be readily tuned to subluminal, superluminal, and even negative values by tailoring the spatio-temporal field structure independently of any material properties. We present an analytical framework and numerical simulations for the propagation of space-time SPPs in comparison with traditional pulsed SPPs whose spatial and temporal degrees of freedom are separable, thereby verifying the propagation-invariance of the former.
Cite
@article{arxiv.2003.02105,
title = {Space-Time Surface Plasmon Polaritons: A New Propagation-Invariant Surface Wave Packet},
author = {Kenneth L. Schepler and Murat Yessenov and Yertay Zhiyenbayev and Ayman F. Abouraddy},
journal= {arXiv preprint arXiv:2003.02105},
year = {2020}
}