High-contrast modulation of light with light by control of surface plasmon polariton wave coupling

TL;DR

This paper introduces a novel light modulation technique using surface plasmon polaritons, achieving high contrast and fast switching times through a nanoscale structural transformation in gallium.

Contribution

It presents a new mechanism for light modulation by controlling plasmon polariton wave coupling via a light-induced structural change in gallium.

Findings

Nearly 10-fold intensity modulation with 15 mJ/cm^2 fluence

Transient switching times of a few tens of nanoseconds

Effective in visible and near-infrared spectral ranges

Abstract

We have demonstrated a new mechanism for modulating light with light by controlling the efficiency with which light is coupled into a plasmon polariton wave. An optical fluence of 15 mJ/cm^2 in the control channel is sufficient to achieve nearly a 10-fold intensity modulation of the signal beam reflected from a Glass/MgF_2/Ga structure. The mechanism depends on a nanoscale light-induced structural transformation in the gallium layer and has transient switching times of the order of a few tens of nanoseconds. It offers high modulation contrast for signals in the visible and near infrared spectral ranges.