Resolving sonoluminescence pulse width with time-correlated single photon counting

The width of the short light pulses emitted from a single air bubble trapped in a resonant sound field in degassed water has been measured for the first time using time-correlated single photon counting. The pulse width at room temperature increases from about 60 ps at low gas concentrations and low driving pressures to more than 250 ps at high gas concentrations and driving pressures at the upper sonoluminescence threshold. The pulse shape is nearly Gaussian and is identical in the red and UV part of the spectrum.