Control of resonant absorption in atoms and molecules with intense XUV electric fields

Speaker:  Christian Ott, Max Planck Institute

Program Description:
With XUV absorption spectroscopy in Fraunhofer-type transmission geometry it is possible to couple directly to state-specific multi-electron transitions in atoms and molecules. Using ultrashort and intense FEL pulses, this creates new opportunities to selectively probe and control the underlying quantum dynamics, with access to the core-level spectroscopic fingerprint of each constituent. Building on our previous experience with laser-dressed modification of attosecond time-resolved resonant absorption line shapes in atoms, in this talk I will introduce our recent activities to explore nonlinear resonant light-matter interactions in small atoms and molecules, imprinted in the absorption spectra of intense XUV-FEL pulses. Last but not least, I will present and discuss first results of combining two formerly independent XUV light sources, FEL pulses and laser-driven high-order harmonics (HHG), in a unique way to probe the state-specific ultrafast dynamics of XUV-excited molecular O2.