Optodynamic Characterization of Laser-Induced Bubbles

P. Gregorčič and J. Možina Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia

Full Text PDF

Received: 3 09 2007;

Laser-induced bubbles can be caused by an optical breakdown in water. They are a result of the optodynamical process where the energy of a high intensity laser pulse is converted into the mechanical energy through an optodynamic conversion. At this process the absorbed optical energy causes plasma expansion that in turn initiates dynamic phenomena: spreading of a shock wave and the development of a cavitation bubble. When the cavitation bubble reaches its maximum radius it starts to collapse due to the pressure of the surrounding liquid. This collapse in turn initiates a new bubble growth and bubble collapse. The process therefore repeats itself, resulting in so-called cavitation-bubble oscillations, with a new shock wave being emitted after every collapse. We present an optodynamic characterization of cavitation bubble's oscillations based on a laser beam-deflection probe. Employed setup enabled us one- or two-dimensional scanning with deflections of a laser probe beam. Deflections were detected with a fast quadrant photodiode.

DOI: 10.12693/APhysPolA.112.1137 PACS numbers: 42.62.-b, 47.40.-x, 47.55.dd