Spatial, Temporal and Spectral Observations of Sonoluminescence by Means of Image Intensification

Sonoluminescence (SL) is a weak light emission occurring when certain liquids are cavitated by acoustical waves. There is at present no single theory that can accommodate all of the experimental observations of this luminescence. Dark adapted eyes, photographic films, and photomultipliers have been used to observe the phenomenon when various transducers and liquids have been used, but little or no spatial information has been available. Long exposures on conventional film have yielded some evidence for standing wave patterns and some information on spectral distributions. The purpose of this paper is to provide a brief history of observations of the phenomenon and the hypotheses put forth to explain it, and to describe some initial experimental results obtained using image intensification to determine the spatial, temporal and spectral characteristics associated with sonoluminescence in water.