Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006

No abstract

Using photoelectron angular streaking by strong circularly polarized laser pulses, we measure angulardependent tunneling rates from the inner orbitals of O 2 in the molecular frame, which correlate with the strong-field molecular dissociative ionization process. We show that the electronic density of molecular inner orbitals can be visualized by angular tunneling rates in the molecular frame. We demonstrate the orbital-by-orbital characterization of tunneling ionization from randomly oriented molecules. Compared with the single-active-electron approximation theories, i.e., the molecular strong-field approximation and the molecular Ammosov-Delone-Krainov model, the experiment shows that the tunneling from the excited states and the state coupling might play an important role in strong-field molecular tunneling ionization. Our results suggest major advances in quantum theory needed for molecular inner orbital tunneling and open intriguing perspectives to probe quantum dynamics related with molecular core electrons.

No abstract

We experimentally investigated dissociative double ionization of CO 2 induced by intense femtosecond laser pulses. Three-dimensional momenta were precisely measured for correlated fragmental ions CO + and O + . The dissociation dynamics of CO 2 2+ was theoretically simulated by using a Coulomb potential approximation. The ultrashort dissociation time (∼400 fs) can well explain the observed anisotropic angular distribution of fragmental ions relative to the laser polarization.