Coloquio Daniel Rivas (invitado por el Prof. Birger Seifert)

"The road to time-resolved nonlinear optics at 100 eV."

"In the past decade, great progress has been made on the study of ultrafast dynamics in atoms and molecules with attosecond time resolution [1]. This progress has been possible thanks to the development of table–top few-cycle optical laser systems with high enough intensities to drive the generation of high-order harmonics of its fundamental frequency (reaching the XUV to soft x-ray spectral region), with durations far below the driving laser’s period. However, the low photon flux yielded so far by this approach has limited this field mainly to studies based on XUV-pump/IR-probe (or vice versa) schemes. Significant efforts have been made to increase the XUV-photon flux in order to extend these studies to pure XUV interactions [2], but until now most of the research in this direction has been limited to large-scale facilities [3], which do not offer an attosecond time resolution, or to high-harmonic sources with relatively low photon energies [4,5].

In this talk I will first briefly introduce the work being done at the Laboratory of Attosecond Physics in Garching, to then report on the development of a high-harmonics source driven by a sub-two-cycle multi-terawatt NIR laser [6]. This source, with a central frequency around 100 eV, allows the isolation of pulses with duration in the attosecond regime and with high enough intensities to study nonlinear ionization dynamics. A preliminary experiment confirming the claimed intensities is presented, to then discuss the future steps towards attosecond-resolution time-resolved nonlinear optics at the XUV and beyond."