Domagoj Pavičić

Small Molecules in Intense Laser Fields - Dissociation and Stabilisation

Small molecules such as H 2 + and D 2 + in an ion beam were investigated in high-intensity laser fields with intensities between 1013 and 5 × 1015 W/cm2. This new research field is characterized by the terms multiphoton absorption, nonlinear processes, light-induced molecular potentials and photon-dressed states. In our ion beam experiment the kinetic energy spectra of the fragments H and H+ were detected with high resolution. The two fragmentation channels observed here exhibit an interesting fine structure not detected before. It can be easily associated in the first one, the dissociation channel, to the vibrational levels of the parent molecules H 2 + and D 2 + , respectively. In the second fragmentation channel, namely in the multiphoton ionization process leading to Coulomb explosion, it was interpreted as charge resonance enhanced ionization (CREI) resulting in the preferred (critical) distances clearly observed here for the first time.