Laser Excitation of the 1S-2S Transition in Singly-Ionized Helium

Elmer L. Gründeman; Vincent Barbé; Andrés Martínez de Velasco; Charlaine Roth; Mathieu Collombon; Julian J. Krauth; Laura S. Dreissen; Richard Taïeb; Kjeld S. E. Eikema

arXiv · 2308.13271

Laser Excitation of the 1S-2S Transition in Singly-Ionized Helium

Elmer L. Gründeman·Vincent Barbé·Andrés Martínez de Velasco·Charlaine Roth·Mathieu Collombon·Julian J. Krauth·Laura S. Dreissen·Richard Taïeb·Kjeld S. E. Eikema

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Abstract

Precision laser spectroscopy in the extreme ultraviolet of the 1S-2S two-photon transition in singly-ionized helium is a promising route for tests of fundamental physics. We demonstrate laser excitation of this transition in an atomic beam of $^3$He, based on an amplified frequency comb pulse at 790 nm combined with its 25$^{\text{th}}$ harmonic at 32 nm. A clear resonance is observed with a maximum excitation probability of close to 10$^{-4}$ per pulse, and the results are well described by our simulations. This paves the way for high-precision Ramsey-comb spectroscopy of a single helium ion in a Paul trap.

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Elmer L. Gründeman, Vincent Barbé, Andrés Martínez de Velasco, Charlaine Roth, Mathieu Collombon, Julian J. Krauth, Laura S. Dreissen, Richard Taïeb, Kjeld S. E. Eikema. 2023-08-25. Laser Excitation of the 1S-2S Transition in Singly-Ionized Helium. https://arxiv.org/abs/2308.13271

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