Acoustic-surface-wave amplitude and phase measurements using laser probes

Abstract

The investigation of acoustic-field distributions on free surfaces is important in several different classes of application. Measurements of the phase of acoustic surface waves using optical probes allow direct measurement of their velocity. A number of different optical-probe types are compared on the basis of sensitivity and stability. The operation and design of an optical heterodyne probe, capable of high-precision phase and group-velocity measurement, is described.