Study of surface acoustic wave scattering and diffraction by scanning acoustic force microscopy

Scanning Acoustic Force Microscopy (SAFM) has been used to study scattering and diffraction phenomena of SAWs (surface acoustic waves) with a spatial resolution on the nanoscale. With other acoustic imaging methods, it has been difficult to achieve both nanometer lateral resolution and sub-A wave amplitude detection sensitivity at the same time. With SAFM, amplitude distribution and phase velocity of arbitrarily polarized modes are accessible on the nanoscale. We present a model of the SAFM contrast formation and give some examples for simple experimental situations. SAW excitation by a single SAW source and the wavefield distribution within an acoustic charge transport structure are examined.