Electron excitation and 'cascade' ionisation of diatomic molecules with ultra-short pulses of strong IR lasers

摘要

The dynamics of molecular electron excitation and ionisation is studied inreal-time for ultra-short IR laser pulses of intensity I>10^{13} W/cm^{2}. Themulti-electron molecule is modeled by a system of two active electrons movingin a field of frozen core. The time dependences of electron probability,electron energy, and one-electron/two-electron ionisation probability arecalculated for example of the N$_{2}$ molecule and the laser pulse withlambda=800 nm, au=5 fs. The electron dynamics of the pulse - excitedmolecule is considered also after the pulse end. The results show that in thestrong IR pulses of Ige 10^{16} W/cm^{2} the molecule undergoes a 'cascade'ionisation, where the one electron is emitted with the same probability as apair of electrons.