Acoustic wavefronts and internal diffraction

Abstract

We have developed new imaging methods for the study of ultrasonic waves in solids. The signal from a point source of ultrasound is detected as a function of space and time, revealing the acoustic wavefront (or group-velocity surface) striking a surface of the solid. By Fourier transforming the x-y-t “data cube” resulting from a short pulse on silicon, the internal diffraction of acoustic waves is observed.