Polarization properties of Raman scattering by surface phonon polaritons in GaAsP nanowires

Sergey I Rybchenko,Huiyun Liu,Sarfraz Ali,Yunyan Zhang

doi:10.1088/1361-6463/ac2400

Sergey I Rybchenko, Huiyun Liu + Show 2 more

Open Access

https://doi.org/10.1088/1361-6463/ac2400

Copy DOI

Abstract

Strong resonant enhancement of Raman scattering on photonic resonance was observed in GaAsP semiconductor nanowires. The enhancement allowed for detailed studies of the surface phonon polariton (SPhP) scattering peak on individual nanowires. In particular, for the first time, the effect of the nanowire cross section shape on SPhP properties has been investigated. It was found that the cross section flattening induces a strong polarisation and a spectral shift of SPhPs supported by such nanowire. The assisting numerical simulations allowed to link the induced polarisation effect to a splitting of the resonant HE11 mode in the flattened nanowire. The observed spectral shift of SPhP has been also theoretically reproduced in elliptical approximation for the flattened cross section. The obtained results pave a ground for engineering of SPhP polarisation response and accurate spectral control of SPhPs in applications utilising the nanowire morphology.

Highlights

Surface phonon polaritons (SPhPs) are quasiparticle excitations associated with surfaces and interfaces of noncentrosymmetric dielectric crystalline materials [1, 2]
Strong resonant enhancement of Raman scattering on photonic resonance was observed in GaAsP semiconductor nanowires
It was found that the cross section flattening induces a strong polarisation and a spectral shift of surface phonon polariton (SPhP) supported by such nanowire

Summary

Introduction

Surface phonon polaritons (SPhPs) are quasiparticle excitations associated with surfaces and interfaces of noncentrosymmetric dielectric crystalline materials [1, 2]. For natural crystalline dielectrics this range is found in far infra-red (IR) spectral window. Arising from far-IR frequency window, SPhPs spectrally overlap with molecular vibrations and they have been considered for developing ultrasensitive molecular spectroscopy [4, 5] and even for alteration of molecular chemical activity [6,7,8]. There have been a sharp increase of interest to SPhPs as an attractive platform for IR miniaturised photonic circuits due to the extremely high compression of free-space

Methods

Results

Conclusion