The study of ultrasonic waves in random media in a strong multiple scattering limit is becoming increasingly relevant to applied techniques of nondestructive characterization of material microstructures. This paper reviews the state of that art within the context of engineering applications and also reviews the evidence for the Anderson Localization of ultrasound.
While ultrasound has long been employed as a nondestructive probe of material microstructure, it has usually been the rapidly attenuated coherent wave, and in particular, its speed and attenuation, which has been scrutinized for that purpose. The theory of such waves is discussed here. However, recent experiments and theory are increasingly addressing the diffuse speckle wave field. This small but growing body of work is also reviewed.
While there has been much work recently on optical and microwave realizations for the study of the Anderson localization of classical waves, there has been little such investigation with sound waves. Recent work demonstrating the Anderson Localization of Ultrasound in two dimensions may be the first such for any classical waves in dimension greater than one.