Perspective: Ultrafast Imaging of Molecular Dynamics Using Ultrafast Low-Frequency Lasers, X-ray Free Electron Laser and Electron Pulses

TL;DR

This paper reviews recent advances in ultrafast imaging techniques that utilize laser, x-ray, and electron sources to capture molecular dynamics with femtosecond resolution, enabling detailed visualization of atomic motions.

Contribution

It provides a comprehensive overview of diverse ultrafast molecular imaging methods and their recent experimental progress in capturing chemical and electronic dynamics.

Findings

High-order harmonic generation imaging enables femtosecond resolution.

Coulomb explosion imaging reveals molecular structures through ion momentum analysis.

Diffraction imaging encodes electronic and structural information in reciprocal space.

Abstract

The requirement of high space-time resolution and brightness is a great challenge for imaging atomic motion and making molecular movies. Important breakthroughs in ultrabright tabletop laser, x-ray and electron sources have enabled the direct imaging of evolving molecular structures in chemical processes. And recent experimental advances in preparing ultrafast laser and electron pulses equipped molecular imaging with femtosecond time resolution. This Perspectives present an overview of versatile imaging methods of molecular dynamics. High-order harmonic generation imaging and photoelectron diffraction imaging are based on laser-induced ionization and rescattering processes. Coulomb explosion imaging retrieves molecular structural information by detecting the momentum vectors of fragmented ions. Diffraction imaging encodes molecular structural and electronic information in reciprocal space. We also present various applications of these ultrafast imaging methods in resolving laser-induced nuclear and electronic dynamics.