Femtosecond spectroscopy of molecular autoionization and fragmentation

Femtosecond laser pulses are applied to the study of the dynamics and the pathways of multiphoton-induced ionization, autoionization, and fragmentation of Na₂ in molecular-beam experiments. In particular, we report on first results obtained studying electronic autoionization (leading to Na₂⁺+e^-) and autoionization-induced fragmentation (leading to Na⁺+Na+e^-) of a bound doubly excited molecular state. The final continuum states are analyzed by photoelectron spectroscopy and by measuring the mass and the released kinetic energy of the corresponding ionic fragments with a time-of-flight arrangement.