Experimental observation of an acoustic field #7

Abstract

In this section, optical techniques used for experimental observation of acoustic fields are reviewed. Acousto-optic interaction is discussed as a basic principle for visualizing inhomogeneity in refractive index fields. Light deflection and diffraction are also discussed as typical phenomena, especially in visualization of ultrasound fields. Three techniques, phase detection, Schlieren, and shadowgraph techniques, are mainly reviewed with discussion of the differences in the principles, optical systems, and acquired images. Background-oriented Schlieren technique, scanning laser Doppler vibrometry, and photoelastic techniques are also discussed as relatively new techniques for visualization of ultrasound fields. A technique that visualizes a distribution of temperature rise generated by ultrasound exposure is also introduced.