ABSTRACT
Acoustic microscopy involves imaging the elastic properties of surface or subsurface regions using acoustic waves as well as measuring the mechanical properties on a microscopic scale. In most of the work done so far, this has involved focusing acoustic waves by an acoustic lens that is mechanically scanned over the field of view. Following the initial work of Sokolov [130], the real start of the field was the development of the scanning acoustic microscope (SAM) by Lemons and Quate in 1973 [131]. This was essentially an extension of the traditional focused C scan ultrasonic imaging system, which is a broadband scanned ultrasonic imaging system using a spherical lens of high
F
number to image surface detail or defects in the interior of opaque samples.
