High-Harmonic Optical Vortex Generation from a Plasma Aperture

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Li, Runze, Yan, Wenchao, Yi, Longqing
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912669877927936
author Li, Runze
Yan, Wenchao
Yi, Longqing
author_facet Li, Runze
Yan, Wenchao
Yi, Longqing
contents When a high-power, femtosecond, circularly polarized (CP) laser pulse is incident on a micrometer-scale aperture in a solid foil target, it drives surface plasma oscillation, generating high-order harmonic vortices in the diffracted light. However, this mechanism has so far only been studied theoretically under ideal conditions. In this work, we perform numerical studies on more realistic situations. In particular, we focus on a scenario where the laser is obliquely incident on the target surface to avoid the potential damage of the optics by the reflected light. We demonstrate that increasing oblique incidence angle, reducing target thickness, and improving laser contrast can enhance the harmonic conversion efficiency. However, the generated harmonic beams may contain both Laguerre-Gaussian (LG) (vortex) and non-LG components under non-ideal conditions. We show that they can be separated by their divergence, as the vortex components has smaller diverging angle. In addition, we have performed computational analyses on the harmonic divergence angles and topological charge spectra of vortex high-order harmonics under different conditions. These high-order harmonic pure LG modes can potentially be filtered out for wide range of fundamental and applied physics researches. This study provides valuable insights for the design and implementation of future experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2510_22091
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle High-Harmonic Optical Vortex Generation from a Plasma Aperture
Li, Runze
Yan, Wenchao
Yi, Longqing
Plasma Physics
When a high-power, femtosecond, circularly polarized (CP) laser pulse is incident on a micrometer-scale aperture in a solid foil target, it drives surface plasma oscillation, generating high-order harmonic vortices in the diffracted light. However, this mechanism has so far only been studied theoretically under ideal conditions. In this work, we perform numerical studies on more realistic situations. In particular, we focus on a scenario where the laser is obliquely incident on the target surface to avoid the potential damage of the optics by the reflected light. We demonstrate that increasing oblique incidence angle, reducing target thickness, and improving laser contrast can enhance the harmonic conversion efficiency. However, the generated harmonic beams may contain both Laguerre-Gaussian (LG) (vortex) and non-LG components under non-ideal conditions. We show that they can be separated by their divergence, as the vortex components has smaller diverging angle. In addition, we have performed computational analyses on the harmonic divergence angles and topological charge spectra of vortex high-order harmonics under different conditions. These high-order harmonic pure LG modes can potentially be filtered out for wide range of fundamental and applied physics researches. This study provides valuable insights for the design and implementation of future experiments.
title High-Harmonic Optical Vortex Generation from a Plasma Aperture
topic Plasma Physics
url https://arxiv.org/abs/2510.22091