title: Arrest of self-focusing collapse in femtosecond air filaments: higher order Kerr or plasma defocusing?
abstract: Experimentally measured conical emission rings on the blue side of the filament supercontinuum of a 800 nm 50 fs pulse in air are reproduced in simulations with plasma and the third-order Kerr as the nonlinear terms. This agreement indicates plasma as the dominant mechanism arresting the self-focusing collapse. The higher order Kerr terms with the recently measured coefficients stop the collapse at a lower intensity than the plasma does and lead to the spherical angle-wavelength spectrum without blueshifted rings.
authors.affiliation: International Laser Center & Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia. kosareva@physics.msu.ru
authors.forename: Olga
authors.initials: O
authors.lastname: Kosareva
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Daigle
authors.forename: Nikolay
authors.initials: N
authors.lastname: Panov
authors.forename: Tiejun
authors.initials: T
authors.lastname: Wang
authors.forename: Sima
authors.initials: S
authors.lastname: Hosseini
authors.forename: Shuai
authors.initials: S
authors.lastname: Yuan
authors.forename: Gilles
authors.initials: G
authors.lastname: Roy
authors.forename: Vladimir
authors.initials: V
authors.lastname: Makarov
authors.forename: See Leang
authors.initials: SL
authors.lastname: Chin