METALLIC CLUSTERS IN STRONG FEMTOSECOND LASER-PULSES

We study the electron response of a Na-9(+) cluster excited by strong femtosecond laser pulses by means of a time-dependent density-function al method. We investigate the full electronic dipolar response and mul tiphoton ionization processes. A strong correlation between induced el ectronic dipole oscillations and electron emission is observed, leadin g to a pronounced resonant enhancement of ionization when using lasers operating at the frequency of the Mie plasmon. We also examine the pr obabilities for producing differently charged ionic states of the syst em.