Abstract
In this paper, we explore the intensity-dependent strong-field double ionization of Ne with orthogonally polarized two-color laser pulses consisting of 800- and 400-nm laser fields. The yield of as a function of the relative phase of the two colors experiences a qualitative transition as the laser intensity decreases from the saturation regime to the far-below-saturation regime. In the saturation regime, our simulations well reproduce the recent experimental observations [Phys. Rev. Lett. 112, 193002 (2014)]. Turning to the far-below-saturation regime, however, we find that the observed small knee structure totally disappears and the maximum yield of is shifted by a phase. This is explained by the competition between the trajectory concentration effect and the -dependent ionization rate of the tunneling electron. The possibility of controlling over the two-electron emission direction along the 400-nm field through the laser intensity is also investigated. We show that the two-electron emission direction can be reversed by changing the laser intensity for some vales of , while this fails for some other values of .
- Received 27 February 2015
DOI:https://doi.org/10.1103/PhysRevA.91.063417
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