Underwater acoustic wave generation by filamentation of terawatt ultrashort laser pulses

Vytautas Jukna (1) , Amélie Jarnac (1) , Carles Milián (2) , Yohann Brelet (1) , Jérôme Carbonnel (1) , Yves-Bernard André (1) , Régine Guillermin (3) , Jean-Pierre Sessarego (3) , Dominique Fattaccioli (4) , André Mysyrowicz (1) , Arnaud Couairon (2) , Aurélien Houard (1)

1 ILM - Interaction Laser-Matière
2 CPHT - Centre de Physique Théorique [Palaiseau]
3 O&I - Ondes et Imagerie
4 DGA Techniques Navales

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.

Domaines: Optique [physics.optics]

Vytautas Jukna, Amélie Jarnac, Carles Milián, Yohann Brelet, Jérôme Carbonnel, et al.. Underwater acoustic wave generation by filamentation of terawatt ultrashort laser pulses. Physical Review E , 2016, 93, pp.063106. ⟨10.1103/PhysRevE.93.063106⟩. ⟨hal-01333275⟩