Elegant high-order harmonic vortices generation

Abstract

High-order harmonic generation is a cornerstone of attosecond science, with applications spanning from spectroscopy to the creation of ultrashort light pulses with temporal duration falling in the attosecond regime. In addition, light beams carrying orbital angular momentum (OAM) allow studies of light–matter interactions mediated by OAM couplings. In this work, we present an alternative approach to generating high-order harmonic vortices using elegant Laguerre–Gaussian (eLG) beams. We examine the spatiotemporal characteristics of these harmonic vortices in the far-field regime and demonstrate how the low divergence of eLG beams makes them suitable for producing extreme ultraviolet (XUV) twisted attosecond pulses. Additionally, by solving the far-field Fraunhofer integral, we analyze the influence of azimuthal and radial indices on the spatial profile of vortex beams, thereby exploring the impact of larger topological charges. This study extends the concept of harmonic vortices generated by Laguerre–Gaussian beams to applications beyond the paraxial approximation.