Single bubble sonoluminescence: Investigations of the emitted pressure wave with a fiber optic probe hydrophone

In single bubble sonoluminescence (SBSL) in addition to the short light pul ses, the bubble emits in the collapse phase a pressure wave that can be mea sured with a fiber optic probe hydrophone with high spatial resolution (100 mu m) and a rise time of 5 ns. In a systematic study we have characterized the width and the amplitude of the emitted pressure wave in dependence of the driving pressure, the gas concentration, and the water temperature. The width of the emitted acoustic wave increases with increasing gas concentra tion and increasing driving pressure from about 7 ns to more than 30 ns in the stability range, where SBSL can be observed. In contrast to the emitted light intensity, the water temperature has only little influence on the em itted acoustic wave. Theoretical considerations using the Gilmore equation show good agreement with the experimental data. [S1063-651X(99)08002-2].