Generation of extreme-ultraviolet beams with time-varying orbital angular momentum

TLDR

Structured light vortex beams carry optical angular momentum and have been used to enhance optical communications and imaging. The authors aim to create dynamic vortex pulses that could manipulate nanostructures and atoms on ultrafast timescales. They generate extreme‑ultraviolet vortex pulses by interfering two time‑delayed vortex beams of different orbital angular momenta via high‑harmonic generation, producing a self‑torque that makes the angular momentum time‑dependent. Published in Science, issue eaaw9486.

Abstract

Pulses with a twist and torque Structured light beams can serve as vortex beams carrying optical angular momentum and have been used to enhance optical communications and imaging. Rego et al. generated dynamic vortex pulses by interfering two incident time-delayed vortex beams with different orbital angular momenta through the process of high harmonic generation. A controlled time delay between the pulses allowed the high harmonic extreme-ultraviolet vortex beam to exhibit a time-dependent angular momentum, called self-torque. Such dynamic vortex pulses could potentially be used to manipulate nanostructures and atoms on ultrafast time scales. Science , this issue p. eaaw9486