# Imaging ultrafast molecular wavepackets with a single chirped UV pulse

## TL;DR

This paper demonstrates how a single chirped UV pulse can emulate pump-probe experiments to image ultrafast molecular dynamics, enabling control over ionization yields and direct mapping of wave packet evolution.

## Contribution

It introduces a method to use a single chirped UV pulse for time-resolved imaging of molecular wavepackets, simplifying experimental setups and enhancing control over ionization processes.

## Key findings

- Chirped UV pulses can encode pump-probe delays in time.
- Wave packet dynamics can be directly mapped via ionization probabilities.
- Ionization yields can be significantly enhanced through chirp tuning.

## Abstract

We show how to emulate a conventional pump-probe scheme using a single frequency-chirped ultrashort UV pulse to obtain a time-resolved image of molecular ultrafast dynamics. The chirp introduces a spectral phase in time that encodes the delay between the pump and the probe frequencies contained in the pulse. By comparing the results of full dimensional ab initio calculations for the H$^+_2$ molecule with those of a simple sequential model, we demonstrate that, by tuning the chirp parameter, two-photon energy-differential ionization probabilities directly map the wave packet dynamics generated in the molecule. As a result, one can also achieve a significant amount of control of the total ionization yields, with a possible enhancement by more than an order of magnitude.