The role of the Kramers-Henneberger atom in the higher-order Kerr effect

摘要

, standard in many ultrafast experiments, suppress the potential barrier for ionization for all excited states in most atoms and molecules. By means of angle resolved photoelectron spectra, we have shown [1] that in this regime the formation of stable “laser-dressed” atoms, the so-called Kramers-Henneberger (KH) atoms [2], plays a crucial role. The response of the “almost-free” states of this atom does not only play a key role in the experimental surprise of the unprecedented acceleration of neutral atoms [3] at the rate of 10