Visualisation of surface acoustic waves

A simple method for acoustic-surface-wave visualisation is described which is applicable to both piezoelectric and non-piezoelectric surfaces. Briefly, a uniform layer of small particles, comparable to the wavelength, is distributed over the acoustic surface. The acoustic-beam pattern of an incident surface wave is then traced out by scattering the particles out of the propagation path. Experiments at 100 MHz on lithium-niobate surfaces are described.