Sonoluminescence

The current status of knowledge of the sonoluminescence mechanism is reviewed. It is shown that the origin of sonoluminescence in multibubble cavitation fields is best described by the local charging theory of cavitation bubbles. For certain acoustic field configurations, a single stably pulsating cavitation bubble develops, which differs from its 'ordinary' counterparts in a number of respects, and whose sonoluminescence is a thermal effect in contrast to the luminescent glow of the ensemble of 'cold' cavitation bubbles. A model of single-bubble sonoluminescence is proposed, which includes the additional resonance absorption of energy by a solitary cavitation bubble in a symmetric acoustic field. The mechanisms of some single-bubble effects are as yet not clear.