Saturation of the Afterbounce Shape Instability in Single Bubble Sonoluminescence; Theory and Experiment

Excitation of the afterbounce instability represents one route to bubble death in single-bubble sonoluminescence. By taking the existing first order theory for excitation of shape instabilities represented by expansion in a spherical harmonic to second order thereby mixing spherical harmonics of different orders, we show that the exponential growth into bubble disruption in a certain parameter regime is checked and a saturated stable state of shape distortion is possible. Experimental evidence provided by Mie scattering is presented and a possible connection to simultaneous spatially anisotropic light emission discussed.