Filamentation of ultra-short TW-class lasers recently opened new perspectives in
atmospheric research. Laser filaments are self-sustained light structures of 0.1–1 mm in …

We discuss the connection between strong-field ionization, saturation of the Kerr response
and the formation of the Kramers–Henneberger (KH) atom and long-living excitations in …

Motivated by the ongoing controversy over the origin of the nonlinear index saturation and
subsequent intensity clam** in femtosecond filaments, we study the atomic nonlinear …

Ultrafast ionization dynamics within the field half cycle is shown to be the key physical factor
that controls the properties of optical nonlinearity as a function of the carrier wavelength and …

Nonlinear optics experiments measuring phase shifts induced in a weak probe pulse by a
strong pump pulse must account for coherent effects that only occur when the pump and …

We show that, in an intense laser field, ultrafast photoionization can occur through quantum
pathways that cannot be categorized as multiphoton ionization or ground-state tunneling. In …

In this paper we propose and demonstrate that the ultrafast nonlinear optical response of
atoms may be accurately calculated in terms of metastable states obtained as solutions of …

We present absolute space-and time-resolved measurements of the ultrafast laser-driven
nonlinear polarizability in argon, krypton, xenon, nitrogen, and oxygen up to ionization …

The nonlinear coefficients, n 4, of the time-dependent refractive index for argon are
calculated in the non-resonant optical regime. Second-order polynomial fitting of DC-Kerr, γ …

We apply a numerical basis-state method to determine the electric susceptibility of atomic
hydrogen via calculations of the terms of the perturbative power series expansion up to …