Underwater acoustic wave generation by filamentation of terawatt   ultrashort laser pulses
  Acoustic signals generated by filamentation of ultrashort TW laser pulses in water are characterized experimentally. Measurements reveal a strong influence of input pulse duration on the shape and intensity of the acoustic wave. Numerical simulations of the laser pulse nonlinear propagation and the subsequent water hydrodynamics and acoustic wave generation show that the strong acoustic emission is related to the mechanism of superfilamention in water. The elongated shape of the plasma volume where energy is deposited drives the far-field profile of the acoustic signal, which takes the form of a radially directed pressure wave with a single oscillation and a very broad spectrum. 
Vytautas Jukna, Amelie Jarnac, Carles Mili\'an, Yohann Brelet,   J\'er\^ome Carbonnel, Yves-Bernard Andr\'e, R\'egine Guille...
physics.optics physics.flu-dyn