Shielding of optical pulses on hydrodynamical time scales in laser-induced breakdown of saline water

Anno: 2014

Autori: Conti-Sanpol D., Marino F., Roati G., Orfila A., Javaloyes J., Piro O., Balle S.

Affiliazione autori: Institut Mediterrani d’Estudis Avancats (CSIC-UIB) Esporles, Spain; CNR-Istituto Nazionale di Ottica, Firenze, Italy; LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, Sesto Fiorentino (FI), Italy; Dept. de Fısica, Univ. Illes Balears, Palma de Mallorca, Spain

Abstract: Pulse shielding in Laser-Induced Breakdown of saline water on hydrodynamic time scales is experimentally characterized. Pairs of pulses from a Nd:YAG laser are focused into saline water with a controlled time delay between them. The Laser-Induced Breakdown produced by the first pulse creates a cavitation bubble that later collapses generating a plume of bubbles that evolves on hydrodynamic time scales. When the second pulse arrives, the light is scattered by this plume with a consequent reduction in the intensity at the focal spot resulting in a lower breakdown efficiency of this pulse. By means of acoustic measurements, we determine the breakdown energy threshold for the first pulse and characterize the shielding of the second pulse as a function of the salinity of the solution, the energy of the pulse, and the inter-pulse interval. A model for the blocking process that takes into account both linear and nonlinear absorption along the path is developed which satisfactorily explains the observations. (C) 2014 AIP Publishing LLC.


Volume: 116 (3)      Da Pagina: 033102  A: 033102

Maggiori informazioni: We acknowledge technical support from Dr. Luca Furfaro (U. du Franche-Compte), and funding from the Direccio General de Recerca, Desenvolupament Tecnologic i Innovacio de la Conselleria d\’Innovacio, Interior i Justicia del Govern de les Illes Balears co-funded by the European Union FEDER funds. J.J. acknowledges financial support from the Ramon y Cajal fellowship. F. Marino acknowledges partial financial support from UIB.
Parole chiavi: fluid dynamics; laser ablation; variational approach; ablation; dynamics
DOI: 10.1063/1.4890313

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