Increased Coherence Length in High-Order Harmonic Generation by a Self-Guided Beam

  • H. R. Lange
  • A. A. Chiron
  • A. Bouhal
  • J.-F. Ripoche
  • P. Breger
  • P. Agostini
  • A. Mysyrowicz

Abstract

The increase of the yield of high-order harmonic generation in gases is a topic of current interest in the search of high-brightness UVX sources. The yield depends on the pump intensity, the jet density, the nonlinear polarizability of the target and the coherence length. The first three parameters have been thoroughly investigated and optimized: the intensity is limited by the saturation of ionisation1, the jet density is limited by the defocusing effects of the free electrons2 and the rare gases offer, to the present knowledge, the most efficient targets3. The coherence length is limited by three different phase-mismatch factors: the medium dispersion, the intensity-dependent atomic phase and the phase-shift due to the focusing geometry (the Goüy phase) normally used to achieve the required intensity. While little can be gained from the weak dispersion of relatively low density gases, the suppression of the focusing geometry is potentially an important source of improvement of harmonic generation that would remove the Goüy phase itself, and also cancel the atomic phase longitudinal gradient. The ideal plane-wave configuration can be approached by different ways. In this contribution we investigate harmonic generation by self-guided beams which can propagate over distances of several tenth of meters 4–7.

Keywords

Harmonic Generation Coherence Length Femtosecond Laser Pulse Geometric Phase Multiphoton Ionisation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    A. l’Huillier, L.-A. Lompré, G. Mainfray and C. Manus: Higher Harmonic Generation in Rare Gases, in: Milhai Gavrila (ed): Atoms in Intense Laser Fields, Academic Press Inc., New York 1992, p. 187Google Scholar
  2. [2]
    C. Altucci, T. Starczewski, E. Mevel, and C.-G. Wahlström: Influence of atomic density in high-order harmonic generation, J. Opt. Soc. Am. B 13, 148 (1996)ADSCrossRefGoogle Scholar
  3. [3]
    C. Lynga, A. l’Huillier and C.-G. Wahlström: High-order Harmonic Generation in Molecular Gases, J. Phys.B 29, 3293 (1996)ADSCrossRefGoogle Scholar
  4. [4]
    J. H. Marburger: Self-Focusing: Theory, Prog. Quantum Electron. 4, 35 (1975).ADSCrossRefGoogle Scholar
  5. [5]
    A. Braun, G. Korn, X. Liu, D. Du, J. Squier, and G. Mourou: Self-channelling of high-peak-power femtosecond laser pulses in air, Opt. Lett. 20, 73 (1995).ADSCrossRefGoogle Scholar
  6. [6]
    E. T. J. Nibbering, P. F. Curley, G. Grillon, B. S. Prade, M. A. Franco, F. Salin, and A. Mysyrowicz: Conical Emission from self-guided femtosecond laser pulses in air, Opt. Lett. 21, 62 (1996).ADSCrossRefGoogle Scholar
  7. [7]
    H.R.Lange, A.Chiron, E.T.J.Nibbering, G.Grillon, J.-F.Ripoche, M.A.Franco, B.Lamouroux, B.S.Prade and A.Mysyrowicz: Anomalous long range propagation of femtosecond laser pulses through air: moving focus or pulse selfguiding?,accepted for publication in Opt. Lett.Google Scholar
  8. [8]
    A. l’Huillier, PH. Balcon, S. Candel, K.J. Schafer and K.J. Kulander: Calculation of high-order harmonic generation processes in Xenon at 1064 nm, Phys. Rev. A. 46 2778 1992CrossRefGoogle Scholar
  9. [9]
    P.B. Corkum: Plasma Perspectives on Strong-Field Multiphoton Ionisation, Phys.Rev.Lett. 73, 1995 (1993)Google Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • H. R. Lange
    • 1
  • A. A. Chiron
    • 2
  • A. Bouhal
    • 1
  • J.-F. Ripoche
    • 1
  • P. Breger
    • 3
  • P. Agostini
    • 3
  • A. Mysyrowicz
    • 1
  1. 1.Laboratoire d’Optique AppliquéeCentre National de la RecherchePalaiseauFrance
  2. 2.Dipartimento di FisicaUniversita di PisaPisaItaly
  3. 3.Servie des Photons, Atomes et MoleculesCentre d’Etudes de SaclayGif sur YvetteFrance

Personalised recommendations