On surface plasmon polariton wavepacket dynamics in metal-dielectric heterostructures

TL;DR

This paper investigates the dynamics of surface plasmon polariton wavepackets in metal-dielectric heterostructures, revealing how dielectric layer thickness influences wavepacket behavior, including Bloch oscillations, through rigorous dispersion analysis.

Contribution

It provides a rigorous calculation of SPP dispersion in heterostructures with variable dielectric thickness and analyzes the resulting wavepacket dynamics and loss channels.

Findings

Dielectric layer thickness acts as an external force on SPPs.

Wavepacket reversal and optical Bloch oscillations can occur.

BO amplitudes are about tens of microns with periods of tens to hundreds of femtoseconds.

Abstract

The WKB equations for dynamics of the surface plasmon polariton (SPP) wavepacket are studied. The dispersion law for the SPP in the metal-dielectric heterostructure with varying thickness of a perforated dielectric layer is rigorously calculated and investigated using the scattering matrix method. Two channels of the SPP wavepacket optical losses related to the absorption in a metal and to the SPP leakage are analyzed. It is shown that change of the dielectric layer thickness acts on the SPP as an external force leading to evolution of its quasimomentum and to the wavepacket reversal or even to the optical Bloch oscillations (BO). Properties of these phenomena are investigated and discussed. Typical values of the BO amplitude are about tens of microns and the period is around tens or hundreds of femtoseconds.