Extracting and launching sub-cycle attosecond dynamics through strong-field ionization

Strong-field ionization (SFI) is a central theme of attosecond physics. With the declared goal of tracking the motion of electrons in real-time, experimental access to the ultrafast time scales of electron dynamics is commonly facilitated by pump-probe schemes using ultrashort extreme ultraviolet (XUV) and near-infrared (NIR) pulses of light. Here, we present two studies employing SFI of Xenon atoms in the regime where the NIR-pump and XUV-probe pulses overlap. First, the sub-cycle buildup structure in the absorption lines of the strong-field generated ions serves as a timing tool to detect deliberatly induced group delays on the XUV pulses with a precision of five attoseconds [1]. Second, a lineshape analysis of the absorption spectra gives direct insight into the dipole response of the ions. Oscillations in the asymmetry and in the absorption line strength are observed, and their NIR intensity dependence is discussed within the context of the underlying electron dynamics.