Heidelberg 2015 – wissenschaftliches Programm
A 27.4: Poster
Mittwoch, 25. März 2015, 17:00–19:00, C/Foyer
Time Delays in Two-Photon Ionization — Jing Su1, •Hongcheng Ni2, Agnieszka Jaron-Becker1, and Andreas Becker1 — 1JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA — 2Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden, Germany
We study the time delays in two-photon ionization of the helium atom. We find that in the case of a nonresonant transition the absorption of the two photons occurs without time delay. In contrast, for a resonant transition a substantial absorption time delay is present, which scales linearly with the duration of the ionizing pulse. The two-photon absorption time delay can be related to the phase acquired during the transition of the electron from the initial ground state to the continuum.