# Spatiotemporal imaging of valence electron motion

## TL;DR

This paper presents an all-optical method for real-time imaging of ultrafast valence electron wave packets with femtosecond resolution, enabling direct observation of electron dynamics in molecules.

## Contribution

It introduces a pump-probe-deflect scheme that captures electron charge oscillations immediately after ionization, surpassing previous orbital imaging limitations.

## Key findings

- Successfully imaged valence electron wave packets in real-time.
- Demonstrated femtosecond temporal resolution in electron imaging.
- Potential to observe charge migration and transfer processes.

## Abstract

Electron motion on the (sub-)femtosecond time scale constitutes the fastest response in many natural phenomena such as light-induced phase transitions and chemical reactions. Whereas static electron densities in single molecules can be imaged in real-space using scanning tunnelling and atomic force microscopy, probing real-time electron motion inside molecules requires ultrafast laser pulses. Here, we demonstrate an all-optical approach to imaging an ultrafast valence electron wave packet in real-time with a time-resolution of a few femtoseconds. We employ a pump-probe-deflect scheme that allows us to prepare an ultrafast wave packet \textit{via} strong-field ionization and directly image the resulting charge oscillations in the residual ion. This approach extends and overcomes limitations in laser-induced orbital imaging and may enable the real-time imaging of electron dynamics following photoionization such as charge migration and charge transfer processes.