# Fully-Tensorial Elastic-Wave Mode-Solver in FEniCS for Stimulated Brillouin Scattering Modeling

## TL;DR

This paper introduces a comprehensive elastic-wave mode solver in FEniCS that accounts for the full tensorial stiffness, enabling detailed simulations of stimulated Brillouin scattering in anisotropic waveguides.

## Contribution

It presents a novel tensorial elastic-wave mode solver in FEniCS, including various approximations and coupling with electromagnetic models for Brillouin scattering analysis.

## Key findings

- Validated the full tensorial model against approximations
- Demonstrated the impact of elastic anisotropy on Brillouin gain
- Provided an open-source tool for integrated elastic and optical simulations

## Abstract

A framework for simulating the elastic-wave modes in waveguides, taking into account the full tensorial nature of the stiffness tensor, is presented and implemented in the open-source finite element solver, FEniCS. Various approximations of the elastic wave equation used in the stimulated Brillouin scattering literature are implemented and their validity and applicability are discussed. The elastic mode-solver is also coupled with an electromagnetic counterpart to study the influence of elastic anisotropies on Brillouin gain.