Laser Physics

, Volume 17, Issue 4, pp 390–400

High-order harmonic generation with a strong laser field and an attosecond-pulse train: The Dirac-Delta comb and monochromatic limits

  • C. Figueira de Morisson Faria
  • P. Salières
Strong Field Phenomena

DOI: 10.1134/S1054660X07040147

Cite this article as:
Figueira de Morisson Faria, C. & Salières, P. Laser Phys. (2007) 17: 390. doi:10.1134/S1054660X07040147

Abstract

In recent publications, it has been shown that high-order harmonic generation can be manipulated by employing a time delayed attosecond-pulse train superposed to a strong, near-infrared laser field. It is an open question, however, which is the most adequate way to approximate the attosecond-pulse train in a semianalytic framework. Employing the strong-field approximation and saddle-point methods, we make a detailed assessment of the spectra obtained by modeling the attosecond-pulse train by either a monochromatic wave or a Dirac-Delta comb. These are the two extreme limits of a real train, which is composed by a finite set of harmonics. Specifically, in the monochromatic limit, we find the downhill and uphill sets of orbits reported in the literature, and analyze their influence on the high-harmonic spectra. We show that, in principle, the downhill trajectories lead to stronger harmonics, and pronounced enhancements in the low plateau region. These features are analyzed in terms of quantum interference effects between pairs of quantum orbits, and compared to those obtained in the Dirac-Delta limit.

PACS numbers

32.80.Wr 32.80.Qk 42.65.Ky 

Copyright information

© MAIK “Nauka/Interperiodica” 2007

Authors and Affiliations

  • C. Figueira de Morisson Faria
    • 1
  • P. Salières
    • 2
  1. 1.Centre for Mathematical ScienceCity University, Northampton SquareLondonUK
  2. 2.CEA-SPAM, Bât. 522Centre d’Etudes de SaclayGif-Sur-YvetteFrance

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