Ultrafast Optical Generation of Coherent Bright and Dark Surface Phonon Polaritons in Nanowires

TL;DR

This paper demonstrates a method using visible ultrafast lasers to generate and resolve coherent surface phonon polaritons in nanowires, enabling new studies of polariton coherence at lower energies.

Contribution

It introduces a novel ultrafast laser technique to generate and distinguish bright and dark surface phonon polaritons in nanowires, advancing polariton coherence research.

Findings

Successful generation of coherent surface phonon polaritons using ultrafast lasers.

Simultaneous creation of bright and dark modes confirmed by experiments and simulations.

Opens new avenues for studying coherence in polariton physics.

Abstract

The coherence of polaritons plays a fundamental role in numerous recent experimental observations, from strong coupling to Bose-Einstein condensation, but accessing the coherence of polaritons is a difficult task due to the high energy of plasmons and excitons. However, surface phonon polaritons offer similar promises at much lower energy. Here, we demonstrate the possibility to use visible ultrafast lasers to generate and time resolve coherent surface phonon polaritons in nanowires. We show that these modes are generated through the ultrafast screening of the surface depletion field. By comparing experiments and FDTD simulations, we show that this method allows the simultaneous generation of dark and bright mode. Our observations open the way to deeper investigations of the role of coherence in the rich polariton physics.