Since the first demonstration of the generation of attosecond pulses (1 as= 10− 18 s) in the
extreme-ultraviolet spectral region, several measurement techniques have been introduced …

Attosecond science offers formidable tools for the investigation of electronic processes at the
heart of important physical processes in atomic, molecular and solid-state physics. In the last …

The ability to control the instantaneous state of light, from high-energy pulses down to the
single-photon level, is an indispensable requirement in photonics. This has, for example …

The past two decades have seen rapid developments in short-pulse X-ray sources, which
have enabled the study of nuclear and electronic dynamics by ultrafast X-ray spectroscopies …

In the 60 years since the invention of the laser, the scientific community has developed
numerous fields of research based on these bright, coherent light sources, including the …

Optical interactions are governed by both spin and angular momentum conservation laws,
which serve as a tool for controlling light–matter interactions or elucidating electron …

The strong ellipticity dependence of high-harmonic generation (HHG) in gases enables
numerous experimental techniques that are nowadays routinely used, for instance, to create …

We generate angularly isolated beams of circularly polarized extreme ultraviolet light
through the first implementation of non-collinear high harmonic generation with circularly …

INTRODUCTION Light beams carry both energy and momentum, which can exert a small
but detectable pressure on objects they illuminate. In 1992, it was realized that light can also …

Symmetry is one of the most generic and useful concepts in science, often leading to
conservation laws and selection rules. Here we formulate a general group theory for …