High-resolution imaging of a single circular surface acoustic wave source:Effects of crystal anisotropy

We present an experimental method for the high-resolution imaging of the ex citation and propagation of surface acoustic waves (SAWs) on anisotropic pi ezoelectric substrates. By employing a scanning acoustic force microscope ( SAFM), we are able to image acoustic waves that are excitable by a single c ircular electrode pair source through the mixing with well-defined referenc e plane waves. We show amplitude and phase images of the point-source wave field, containing the angular dependence of the phase velocity of these mod es, as well as their electromechanical coupling strength. The SAFM allows e asy access to acoustic material properties, which are important for the des ign of commercial SAW devices. (C) 2001 American Institute of Physics.