Atomic, molecular and optical physics applications of longitudinally coherent and narrow bandwidth Free-Electron Lasers

TL;DR

This paper discusses the development and applications of longitudinally coherent, narrow bandwidth Free-Electron Lasers (FELs) in X-ray science, highlighting their enhanced coherence properties and potential for high-resolution and coherent control experiments.

Contribution

It presents advancements in FEL technology achieving good longitudinal coherence and illustrates various experiments leveraging this property in chemical, physical, and biological research.

Findings

Achieved narrow bandwidth in FELs for improved longitudinal coherence

Demonstrated applications in high-resolution and coherent control experiments

Extended laboratory laser techniques to short wavelengths with FELs

Abstract

Short wavelength Free-Electron Lasers (FELs) are the newest light sources available to scientists to probe a wide range of phenomena, with chemical, physical and biological applications, using soft and hard X-rays. These sources include the currently most powerful light sources in the world (hard X-ray sources) and are characterised by extremely high powers and high transverse coherence, but the first FELs had reduced longitudinal coherence. Now it is possible to achieve good longitudinal coherence (narrow bandwidth in the frequency domain) and here we discuss and illustrate a range of experiments utilising this property, and their underlying physics. The primary applications are those which require high resolution (for example resonant experiments), or temporal coherence (for example coherent control experiments). The currently available light sources extend the vast range of laboratory laser techniques to short wavelengths.