6533b7d3fe1ef96bd12609f9
RESEARCH PRODUCT
Strong-field-ionization suppression by light-field control
Lars Bojer MadsenEsa RäsänenEsa Räsänensubject
Physicsta114Ionization0103 physical sciencesStrong fieldAtomic physics010306 general physics01 natural sciences114 Physical sciencesAtomic and Molecular Physics and OpticsLight field010305 fluids & plasmasdescription
In recent attempts to control strong-field phenomena such as molecular dissociation, undesired ionization sometimes seriously limited the outcome. In this work we examine the capability of quantum optimal control theory to suppress the ionization by rational pulse shaping. Using a simple model system and the ground-state occupation as the target functional, we show that optimal control generally leads to a significant suppression of the ionization, although the fluence and the pulse length are kept fixed. In the low-frequency regime the ionization is reduced mainly by avoiding high peaks in the intensity and thus preventing tunneling. In contrast, at high frequencies in the extreme ultraviolet regime the optimized pulses strongly couple with the (de)-excitations of the system, which leads to different pulse characteristics. Finally, we show that the applied target functional works, to some extent, for the enhancement of the high-order-harmonic generation, although further developments in optimal control theory to find proper target functionals are required. Peer reviewed
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-09-25 |