Modeling of the micro-focused Brillouin light scattering spectra

TL;DR

This paper presents a semi-analytical model for micro-focused Brillouin light scattering spectra, enabling better theoretical understanding and analysis of experimental data in various applications.

Contribution

A novel semi-analytical model based on the mesoscopic medium approach for micro-focused Brillouin light scattering spectra.

Findings

Model successfully applied to thermal and spin wave measurements

Provides a general framework applicable to various BLS experiments

Enhances analytical capabilities for mechanobiology and device characterization

Abstract

Although micro-focused Brillouin light scattering (BLS) has been used for more than twenty years, it lacks a complete theoretical description. This complicates the analysis of experimental data and significantly limits the information that can be obtained. To fill this knowledge gap, we have developed a semi-analytical model based on the mesoscopic continuous medium approach. The model consists of the following steps: calculation of the incident electric field and the dynamic susceptibility, calculation of the induced polarisation, and calculation of the emitted electric field and its propagation towards the detector. We demonstrate the model on the examples of the measurements of thermal and coherently excited spin waves. However, the used approach is general and can describe any micro-focused Brillouin light scattering experiment. The model can also bring new analytical approaches to mechanobiology experiments or to characterization of acoustic wave based devices.