Manfred Lein, Institut für Theoretische Physik, Leibnitz Universität Hannover, Hannover, Germany

In the recent experiment by Shafir et al. [Nature 2012], high-harmonic generation was used to investigate the timing of electron release in laser-induced ionization of atoms. This scheme requires a two-color field with a weak second harmonic polarized orthogonal to the fundamental driving field. The two observables are the harmonic signal and the ratio of even to odd harmonics as a function of the two-color delay (the phase difference between the two orthogonally polarized fields). From these observables, the ionization and return times of the electron can be retrieved by assuming that the electron responds as a classical particle to the weak second harmonic field. I will first revisit the three-step model and the quantum-orbit model of high-harmonic generation, which are the standard models commonly used to find the ionization and return time. Then I explain the retrieval method in detail. I discuss the calibration of the two-color delay used in the analysis of the experiment and the validity of the classical equations.

Time: 13.30 - 16.00