Laser excitation of the 1S–2S transition in singly-ionized helium
Laser spectroscopy of atomic hydrogen and hydrogen-like atoms is a powerful tool for tests of fundamental physics. The 1<i>S</i>-2<i>S</i> transition of hydrogen in particular is a cornerstone for stringent Quantum Electrodynamics (QED) tests and for an accurate determination of the Rydberg constant. We report laser excitation of the 1<i>S</i>-2<i>S</i> transition in singly-ionized helium (<sup>3</sup>He<sup>+</sup>), a hydrogen-like ion with much higher sensitivity to QED than hydrogen itself. The transition requires two-photon excitation in the challenging extreme ultraviolet wavelength range, which we achieve with a tabletop coherent laser system suitable for precision spectroscopy. The transition is excited by combining an ultrafast amplified pulse at 790 nm (derived from a frequency comb laser) with its 25th harmonic at 32 nm (produced by high-harmonic generation). The results are well described by our simulations and we achieve a sizable 2S excitation fraction of 10<sup>-4</sup> per pulse, paving the way for future precision studies.
Authors
- Laura S. Dreissen (ORCID: https://orcid.org/0000-0002-5659-7577)
- Richard Taïeb (ORCID: https://orcid.org/0000-0001-6301-6008)
- Charlaine Roth (ORCID: https://orcid.org/0000-0002-0508-5088)
- Julian J. Krauth (ORCID: https://orcid.org/0000-0001-7769-650X)
- Mathieu Collombon
- Vincent Barbé (ORCID: https://orcid.org/0000-0003-2414-9099)
- Andrés Martínez de Velasco
- Elmer L. Gründeman (ORCID: https://orcid.org/0000-0001-9253-0380)
- K. S. E. Eikema (ORCID: https://orcid.org/0000-0002-2546-3584)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Johannes Gutenberg University Mainz (DE)
- Aix-Marseille Université (FR)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Sorbonne Université (FR)
- Max Planck Institute of Quantum Optics (DE)
- CEA Paris-Saclay (FR)
- Laboratoire de Chimie Physique - Matière et Rayonnement (FR)
- Institut Parisien de Chimie Moléculaire (FR)
- Physique des interactions ioniques et moléculaires (FR)
- Vrije Universiteit Amsterdam (NL)
Publication Details
- Journal
- Communications Physics
- Published
- 2024-12-19
- DOI
- https://doi.org/10.1038/s42005-024-01891-4
- Citations
- 1
- Primary Topic
- Atomic and Molecular Physics
- Type
- article
- Field-Weighted Citation Impact
- 0.34
Funders
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek