Attosecond technology

Our research is focused on the generation of isolated attosecond pulses with a tunable spectrum spanning from the ultraviolet (240 nm) to the soft-x region (< 5 nm). We implement these pulses in cutting-edge attosecond-resolution pump-probe schemes, to investigate photo-induced ultrafast electron dynamics in a large range of physical systems, with particular interest for biochemically relevant molecules and nanoplasmonic systems.

Pump-probe schemes:

UV - XUV

An isolated UV pulse, with a duration around 1 fs, is combined to a sub-300-as isolated XUV pulse. The UV is typically used to populate excited electronic states of a neutral molecular target and trigger the subsequent ultrafast dynamics. Then, the photo-induced dynamics is probed with attosecond resolution via photoionisation by the XUV pulse (see attosecond spectroscopy in biologically relevant molecules).

XUV - VIS/IR

An isolated sub-300-as XUV pulse is combined with a sub-4-fs visible/near-infrared (VIS/NIR) pulse. The XUV pulse photoionizes the target. The VIS/NIR is used to probe the ultrafast electron dynamics induced by the photoionization. This scheme, implemented in the fashion of streaking spectroscopy, is an excellent tool to track in real time the electron motion in nano-size particles (see attosecond spectroscopy of nanosystems).

SoftX - VIS/IR or UV

The possibility of tuning the spectral range of the isolated attosecond pulses up to the soft-x region allows one to introduce a new regime of experiments, where the core-electron photoionization turns to be highly site-selective (exploiting atomic absorption edges). This approach opens a new perspective in the investigation of ultrafast electron dynamics in matter.