Abstract
We propose an experimental technique for forming a spherical gaseous bubble in highly viscous liquids and observing subsequent free oscillation of the bubble. A nanosecond laser pulse of wavelength 532 nm and energy up to 1.5 mJ is focused into glycerin-water mixtures to create plasma that recombines and deposits heat locally in the focal spot. The subsequent vaporization leads to the growth of a spherical vapor bubble, while gases dissolved in the liquid come into the bubble. When the bubble reaches its maximum size, the bubble temperature decreases so that vapor condenses back into the liquid. The subsequent free oscillation of the micron-sized gas bubble is visualized using a high-speed camera. To quantify damping mechanisms in the bubble dynamics, we compare the measurements to nonlinear Rayleigh-Plesset-type calculations that account for dissipation effects (liquid viscosity, heat conduction and acoustic radiation).
