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

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.