Acoustic microscopy of interior planes

Abstract

It has been recently demonstrated that the acoustic microscope can be used to image planes relatively deep beneath the surface with a lateral resolution of approximately one acoustic wavelength. In order to minimize the aberration effects caused by refraction at the liquid‐solid interface, liquid gallium is substituted for water as the coupling liquid, and mode conversion to shear waves within the solid is exploited. The imaging properties of this system are discussed from a geometrical viewpoint and some experimental results are presented.