Two-Dimensional Phononic Crystal Based on Fused Silica with Hexagonal Symmetry

A two-dimensional phononic crystal based on fused silica with hexagonal symmetry is considered. By solving the wave equation of elastic waves propagation in a periodic medium with the finite element method, the band structure of the phononic crystal is obtained. Based on an analysis of the dispersion relation of acoustic waves propagating in a periodic medium, the acoustic characteristics of the phononic crystal are calculated. Particular attention is paid to the analysis of the acoustic slowness distribution of the phononic modes in the unit cell plane. It is shown that the excitation frequency of acoustic modes controls the numerical values and anisotropy of phase velocities. The work is carried out in the application to acousto-optics.