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arXiv · 1404.6180

High-order harmonic generation at high laser intensities beyond the tunnel regime

J. A. Pérez-Hernández·M. F. Ciappina·M. Lewenstein·A. Zaïr·L. Roso
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Abstract

We present studies of high-order harmonic generation (HHG) at laser intensities well above saturation. We use driving laser pulses which present a particular electron dynamics in the turn-on stage. Our results predict an increasing on the harmonic yield, after an initial dropping, when the laser intensity is increased. This fact contradicts the general belief of a progressive degradation of the harmonic emission at ultrahigh intensities. We have identified a particular set of trajectories which emerges in the turn-on stage of these singular laser pulses, responsible of the unexpected growth on the harmonic efficiency at this high intensity regime. Our study combines two complementary approaches: classical analysis and full quantum mechanical calculations resulting from the numerical integration of the 3-dimensional time-dependent Schrödinger equation complemented with the time-frequency analysis.

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J. A. Pérez-Hernández, M. F. Ciappina, M. Lewenstein, A. Zaïr, L. Roso. 2014-04-24. High-order harmonic generation at high laser intensities beyond the tunnel regime. https://doi.org/10.1140/epjd%2Fe2014-50086-6

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