Evidence for gas exchange in single-bubble sonoluminescence

In this letter we describe measurements of the light emission evolution for single-bubble sonoluminescence. In particular, we show that the evolution of intensity for an air bubble depends on whether or not the bubble has previously been in a steady sonoluminescence state. Our results provide strong experimental evidence in support of the recent hypothesis that an air bubble undergoing single-bubble sonoluminescence in water transitions to an argon bubble.