https://doi.org/10.1140/epjqt/s40507-025-00357-y
Research
High-performance in-vacuum optical system for quantum optics experiments in a Penning-trap
1
Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, 18071, Granada, Spain
2
Centro de Investigación en Tecnologías de la Información y las Comunicaciones, Universidad de Granada, 18071, Granada, Spain
Received:
28
May
2024
Accepted:
30
April
2025
Published online:
22
May
2025
Accurate measurements with implications in many branches of physics have been accessed using conventional techniques in Penning traps within a temperature regime where each eigenmotion of a charged particle is still a classical harmonic oscillator. Cooling the particle directly or indirectly with lasers allows reaching the quantum regime of each oscillator, controlling subtle effects in the precision frontier by detecting photons instead of electric currents. In this paper, we present a new in-vacuum optical system designed to detect 397-nm fluorescence photons from individual calcium ions and Coulomb crystals in a 7-T Penning trap. Based on the outcome of computer simulations, our design shows diffraction-limited performance. The system has been characterized using a single laser-cooled ion as a point-like source, reaching a final resolution of 3.69(3) μm and 2.75(3) μm for the trap’s axial and radial directions, respectively, after correcting aberrations.
Key words: Trapped ions / Optical systems
© The Author(s) 2025
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