Finite element analysis of surface acoustic waves in high aspect ratio electrodes

This paper elaborates on how the finite element method is employed to model surface acoustic waves generated by high aspect ratio electrodes and their interaction with optical waves in a waveguide. With a periodic model it is shown that these electrodes act as a mechanical resonator which slows down the SAWvelocity because of mechanical energy storage.

A finite model is furthermore employed to study the acousto-optical interaction and shows that it is possible to get a bigger change in effective refractive index with these surface acoustic waves compared to using conventional interdigital transducers. Thus, this indicates a way to improve acousto-optical interaction.