Imaging an aligned polyatomic molecule with laser-induced electron diffraction

TL;DR

This paper develops a method using laser-induced electron diffraction with a high-repetition-rate laser and 3D coincidence detection to image multiple bond lengths in aligned polyatomic molecules, advancing ultrafast molecular imaging.

Contribution

It introduces a novel approach for retrieving multiple bond lengths in polyatomic molecules, extending laser-induced electron diffraction beyond simple diatomics.

Findings

Successfully measured C-C and C-H bond lengths in aligned acetylene.

Demonstrated imaging of ultrafast structural changes with femtosecond resolution.

Provided a robust method for complex molecule imaging with high temporal precision.

Abstract

Laser-induced electron diffraction is an evolving tabletop method, which aims to image ultrafast structural changes in gas-phase polyatomic molecules with sub-{\AA}ngstr\"om spatial and femtosecond temporal resolution. Here, we provide the general foundation for the retrieval of multiple bond lengths from a polyatomic molecule by simultaneously measuring the C-C and C-H bond lengths in aligned acetylene. Our approach takes the method beyond the hitherto achieved imaging of simple diatomic molecules and is based upon the combination of a 160 kHz mid-IR few-cycle laser source with full three-dimensional electron-ion coincidence detection. Our technique provides an accessible and robust route towards imaging ultrafast processes in complex gas phase molecules with atto- to femto-second temporal resolution.