As part of the department of nano- and microcharacterization at IPS, the Femtosec group performs research with time-resolved x-ray scattering and spectroscopy, in particular for the analysis of nanoscale dynamics, phonon excitation or phase transitions in the condensed phase. A special emphasis is on the exploitation of the „low alpha mode“ at ANKA, which is capable to deliver pulses as short as 1 picosecond. In the x-ray regime this can be used for pump-probe experiments with femtosecond laser excitation, while in the THz region the coherent emission of the radiation can be sampled by means of electro-optical techniques.
The Femtolab clusters expertise on ultrafast optical methods and pulse lasers, which serve the Femtosec group, but also diagnostics of the electron pulses in the ring and the development of new accelerator concepts and techniques.
The research is funded by ANKA/ISS and by individual grants of the German Science foundation (DFG). AP is funded by the Heisenberg fellowship in 2009-2011. Collaborations are related to the Center for Applied Photonics (CAP) Konstanz. We acknowledge the support and provision of beam time by IPS, SLS and ESRF.
The research of the group can be roughly sorted along the following subjects:
- Laser control of materials via lattice excitation
- Structural dynamics of nanoparticles
- Nanoparticle synthesis
- New Sources and methods with ultrahigh time resolution
Nanoscience explores the spatial region in between bulk material and its atomic or molecular constituents. The change of physical properties can be abrupt and display a number of novel properties. The exploitation of experimental methods, which can both resolve the structure and the temporal dynamics of the nanostructures are inherent to the understanding of this class of systems. We use synchrotron radiation scattering methods for static and dynamic studies and laser based ultrafast methods for the dynamic characterization of nanoscale matter, molecules and crystalline materials.
Central questions are:
- Can light pulses manipulate the phase of functional materials; can one use such effects to switch ferroelectrics, for instance? What are the mechanisms down to an atomic level ?
- Can one watch molecules during the course of a chemical reaction ?
- How do metallic nanoparticles, or nanoparticles with bound proteins, react upon irradiation with intense light pulses ? Can one use these reactions to achieve material processing on a nanoscale, can one achieve targeted effects in biologic materials ?