Strongly localized acoustic surface waves propagating along a V-groove

Strongly localized acoustic surface waves propagating along an immersed V-groove are numerically analyzed and experimentally demonstrated. We analyze the dispersion relation and the distribution of displacements of such groove waves using the compact two-dimensional finite-difference time-domain method. It is shown that they are dispersionless and strongly confined in the lateral cross section. The variations in their velocities as a function of the apex angle are also presented. Furthermore, we implement experimental observation by the near-field detection of these predicted waves in the 30° polymethyl methacrylate groove. The experimental measurements of the wave velocities agree very well with the numerical results.