Transition from plasma- to Kerr-driven laser filamentation

P. Béjot (1, 2) , E. Hertz (1) , J. Kasparian (2) , B. Lavorel (1) , J.-P. Wolf (2) , O. Faucher (1)

1 ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne
2 GAP - Group of Applied Physics [Geneva]

While filaments are generally interpreted as a dynamic balance between Kerr focusing and plasma defocusing, the role of the higher-order Kerr effect (HOKE) is actively debated as a potentially dominant defocusing contribution to filament stabilization. In a pump-probe experiment supported by numerical simulations, we demonstrate the transition between two distinct filamentation regimes at 800 nm. For long pulses (1.2 ps), the plasma substantially contributes to filamentation, while this contribution vanishes for short pulses (70 fs). These results confirm the occurrence, in adequate conditions, of filamentation driven by the HOKE rather than by plasma.

Mots clés: Laser filamentation; Femtosecond phenomena; Plasmas; Ultrafast nonlinear optics; Self-focusing; Optical Kerr effect

Domaines: Physique Atomique [physics.atom-ph]

P. Béjot, E. Hertz, J. Kasparian, B. Lavorel, J.-P. Wolf, et al.. Transition from plasma- to Kerr-driven laser filamentation. Physical Review Letters, 2011, 106, pp.243902. ⟨10.1103/PhysRevLett.106.243902⟩. ⟨hal-00639288⟩