Luminescence characteristics of laser-induced bubbles in water

The luminescence characteristics of laser-created bubbles in water have been studied for pressures between 1 and 15 bars. A fast peak in the luminescence is correlated with the first collapse point of the bubble. The width of the light pulse is several nanoseconds, and increases with the bubble size. With increasing pressure two fast peaks are observed, separated by tens of nanoseconds; this is found to arise from an instability when the bubble splits into two at the collapse. The luminescence is independent of whether the water contains ambient dissolved air, is completely degassed, or is filled with 150 torr partial pressure of argon gas or 1 bar of xenon gas.