A new scientific frontier opened in 2009 with the start of operations of the world's first x-ray
free-electron laser (FEL), the Linac Coherent Light Source (LCLS), at SLAC National …

Terahertz (THz) light has proven to be a fine tool to probe and control quasi-particles and
collective excitations in solids, to drive phase transitions and associated changes in material …

The metal centres in metalloenzymes and molecular catalysts are responsible for the
rearrangement of atoms and electrons during complex chemical reactions, and they enable …

Over more than a century, X-rays have transformed our understanding of the fundamental
structure of matter and have been an indispensable tool for chemistry, physics, biology …

This review is focused on free-electron lasers (FELs) in the hard to soft x-ray regime. The
aim is to provide newcomers to the area with insights into: the basic physics of FELs, the …

X-ray free-electron lasers are unique sources of high-brightness coherent radiation.
However, existing devices supply only linearly polarized light, precluding studies of chiral …

The pulse duration, and, more generally, the temporal intensity profile of free-electron laser
(FEL) pulses, is of utmost importance for exploring the new perspectives offered by FELs; it …

It is a long-standing challenge for laser technologies to generate intense fully coherent
pulses in the x-ray regime. Here, we demonstrate an external seeding mechanism, termed …

The advent of free-electron laser (FEL) sources delivering two synchronized pulses of
different wavelengths (or colours) has made available a whole range of novel pump–probe …

The first steps in photochemical processes, such as photosynthesis or animal vision, involve
changes in electronic and geometric structure on extremely short time scales. Time-resolved …