Heidelberg 1999 – wissenschaftliches Programm
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SYLF: Symposium Wechselwirkung in starken Laserfeldern
SYLF II: HV II
SYLF II.1: Hauptvortrag
Montag, 15. März 1999, 10:30–11:00, zo1
Temporal and spectral tayloring of high-order harmonics — •Maciej Lewenstein1, Pascal Salières2, and Philippe Antoine3 — 1Institut für Theoretische Physik, Universität Hannover, D-30167 Hannover — 2CEA/DSM/DRECAM/SPAM, Service des Photons, Atomes, et Molècules, Centre d’Etudes de Saclay, F-91191 Gif-sur-Yvette Cedex — 3LPAM, Université Catholique de Louvain, chemin du cyclotron, B-1348 Louvain-la-Neuve
I will discuss from theoretical point of view
high-order harmonic
generation by low-frequency laser fields.
In particular, I will discuss the role of dynamically induced
phases of the atomic polarization in determining the optimal
phase matching conditions of harmonics.
I will demonstrate how
the phase matching and the spatial coherence
can be controlled by changing the focusing
parameters of the fundamental laser beam.
I will discuss how the intensity dependence of the dynamically
induced phase leads to a chirp of the harmonic frequency,
and how the focusing conditions and chirped driving fields
can be used to control
the individual harmonic spectra and time profiles.
Temporally, the individual harmonic
pulse can be recompressed to very small durations. Compression
of several harmonics allows to generate pulse trains whose shape
can be arbitrarily taylored.
Spectrally, chirping of the fundamental beam may be employed to compensate
the dynamically induced chirp and to control the individual
harmonic spectrum. Finally, I will discuss
the short pulse effects, in particular
nonadiabatic phenomena and the possibility of generating attosecond pulses.