Selection rules for Brillouin light scattering from eigenvibrations of a sphere

TL;DR

This paper derives group-theoretic selection rules for Brillouin light scattering from vibrational modes of submicron spheres and verifies them with experimental spectral data.

Contribution

It introduces a theoretical framework for understanding light scattering from small spheres and confirms it with experimental results.

Findings

Selection rules accurately predict observed spectra

Experimental data matches theoretical predictions

Group theory effectively describes vibrational scattering

Abstract

Selection rules governing Brillouin light scattering from the vibrational eigenmodes of a homogeneous, free-surface submicron sphere have been derived using group theory. The derivation is for the condition where the sphere diameter is of the order of the excitation light wavelength. Well-resolved spectral data obtained from Brillouin light scattering from submicron silica spheres provide experimental verification of the selection rules.