Nano-Optics and Ultrafast Dynamics
We investigate ultrafast electronic and structural dynamics in solids, nanostructures and surfaces. In particular, the group develops and applies new experimental techniques based on imaging and diffraction with ultrashort electron pulses. We operate unique instruments combining high spatial and temporal resolution, such as an Ultrafast Transmission Electron Microscope (UTEM) and Ultrafast Low-Energy Electron Diffraction (ULEED) setups.
In further activities, we study highly nonlinear optical processes in metallic nanostructures and their control by intense optical fields. Moreover, we have recently established laboratory-scale magnetic imaging using extreme-ultraviolet radiation from high-harmonic generation.
The Göttingen Ultrafast Transmission Electron Microscope (UTEM) is based on a laser-driven field emission photocathode generating electron pulses with femtosecond to attosecond durations. The high spatial coherence and ultrashort duration of the electron beam allows for investigations of structural, electronic and spin dynamics in solid-state systems.
Ultrafast Low-Energy Electron Diffraction (ULEED) enables the study of structural dynamics with ultimate surface sensitivity. Our ULEED setup features a laser-triggered tip emitter in a nanofabricated electron gun environment, providing for high momentum resolution in diffraction.
High Harmonic Generation (HHG) delivers extreme-ultraviolet femtosecond light pulses, which are suitable for time-resolved measurements in solids. Our polarization-controlled HHG sources are employed in the ultrafast imaging of magnetic structures and the spectroscopy of correlated materials.