Higher-order Kerr terms allow ionization-free filamentation in gases

P. Béjot (1, 2) , J. Kasparian (2) , S. Henin (2) , V. Loriot (1) , T. Vieillard (1) , E. Hertz (1) , O. Faucher (1) , B. Lavorel (1) , J.-P. Wolf (2)

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

We show that higher-order nonlinear indices (n4 , n6 , n8 , n10) provide the main defocusing contribution to self-channeling of ultrashort laser pulses in air and Argon at 800 nm, in contrast with the previously accepted mechanism of filamentation where plasma was considered as the dominant defocusing process. Their consideration allows to reproduce experimentally observed intensities and plasma densities in self-guided filaments.

Keywords: Laser filamentation; Molecular alignment; Femtosecond phenomena; Plasmas; Ultrafast nonlinear optics; Self-focusing; Optical Kerr effect

Domains: Atomic Physics [physics.atom-ph]

P. Béjot, J. Kasparian, S. Henin, V. Loriot, T. Vieillard, et al.. Higher-order Kerr terms allow ionization-free filamentation in gases. Physical Review Letters, 2010, 104, pp.103903. ⟨hal-00464524⟩