Wide-band acoustic spectroscopy of biological material based on a laser-induced grating technique

A laser-induced transient grating technique enables fast noncontact acousti c measurements on transparent biological materials in a frequency range fro m tens of megahertz to 1 GHz, We have applied this method to the characteri zation of bovine vitreous and found high-frequency acoustic attenuation val ues to be close to those of water, with a quadratic dependence on frequency , in contrast to low-frequency data. The potential of the technique for stu dying other biological materials, such as human stratum corneum, is demonst rated. (C) 1999 World Federation for Ultrasound in Medicine & Biology.