Hannover 2016 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 24: Interaction with strong or short laser pulses I
A 24.6: Vortrag
Mittwoch, 2. März 2016, 12:15–12:30, f303
Optical response in femtosecond filaments dominated by resonantly enhanced ionization — •Michael Hofmann1,2 and Carsten Brée1,3 — 1Weierstraß Institut für angewandte Analysis und Stochastik (WIAS) — 2Institut für theoretische Physik, TU Berlin — 3Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI)
Although the standard model of femtosecond filamentation is quite successful in many applications, its validity has been under discussion over the last years (initiated by [1]).
For example, the employed ionization rate does not account for resonances between laser-dressed states.
We show exemplarily for a hydrogen atom that resonances locally enhance the ionization which in turn saturates the nonlinear refractive index [2].
Such a saturation can easily be misinterpreted as a higher-order Kerr effect if resonances are neglected.
By modifying the standard model to include resonantly enhanced ionization, we obtain a remarkable agreement between model and TDSE simulations in the adiabatic regime of a slowly varying pulse envelope.
Our goal is to go beyond this adiabatic regime and to derive the optical response for arbitrary pulses without the need to solve the time-dependent Schrödinger equation, thus keeping large-scale filament simulations feasible.
[1] Loriot et al., Opt. Express 17 13429 (2009).
[2] Hofmann and Brée, Phys. Rev. A 92 013813 (2015).