Resonance Enhanced Multiphoton Ionization Spectra of Molecules and Molecular Fragments and Femtosecond Energy- and Angle-Resolved Pump-Probe Photoelectron Spectra

摘要

We have completed studies of ion rotational distributions produced by resonance multiphoton ionization of molecules, molecular fragments and small clusters such as NaH2O and NaNH3. Our key objective was to provide a robust analysis and prediction of spectral features of interest in related experimental studies and technological applications of laser driven ionization. We have also extended our studies of photoelectron spectroscopy from the energy domain to the ultrafast time domain with an emphasis on exploiting femtosecond energy- and angle-resolved photoelectron spectra for real-time mapping of wavepacket motion in molecular systems. We have developed a formulation of time-resolved photoelectron spectroscopy that is well suited for such applications. Results of applications provide compelling evidence of the unprecedented insight that such spectra can provide into both wavepacket motion and the evolution of the associated electronic structure. This capability shows significant promise as a probe of wavepacket motion in regions of avoided crossings (nonadiabatic behavior).