1206.4906 (Pierre Béjot et al.)

On quantum mechanical origin of higher-order Kerr effect in gases:
Channel closure and resonances    [PDF]

Pierre Béjot, Eric Cormier, Edouard Hertz, Bruno Lavorel, Jérôme Kasparian, Jean-Pierre Wolf, Olivier Faucher

We perform full 3D time-dependent Schr\"odinger equation (TDSE) in atomic hydrogen under strong-field excitation. Our calculation reveals a supplementary, quasi-instantaneous negative term as compared to the weak-field model of polarizability widely used to evaluate the non-linear refractive index. This term is closely related to ionization channel closure, providing an interpretation to the similar inversion intensities observed experimentally in various gases. It stems from the interaction of the electrons promoted into the continuum with their parent atom, which imposes to consider an effective electron mass during the pulse duration.

View original: http://arxiv.org/abs/1206.4906