Abnormal pulse duration dependence of the ionization probability of Na atoms in intense laser fields

X M Tong, Z X Zhao, C D Lin
2003 Journal of Physics B: Atomic, Molecular and Optical Physics  
We studied the ionization probability of Na atoms in an intense Ti-sapphire laser at 800 nm versus the laser pulse duration. The ionization probabilities for the Na(3s) and Na(3p) states were found to vary non-monotonically with the pulse duration at a constant peak laser intensity. The abnormal (non-monotonic) pulse duration dependence was traced to the competition between resonant and non-resonant multiphoton ionization processes, which occurs when the frequency broadening due to the finite
more » ... due to the finite pulse duration is compatible with the energy difference between the excitation energy and multiphoton energy.
doi:10.1088/0953-4075/36/6/304 fatcat:4c6vubja3fenvigbl3swrat7ny