Properties of a definition of the SI second based on several optical transitions
Abstract The current definition of the System of unit second based on the Cs ground state hyperfine transition is expected to be replaced by a new definition based on optical frequency standards in the next decade. Several options are currently under consideration for the new definition, including a definition based on the weighted geometric mean of several transitions. In this paper, we review several properties of this option, and most notably introduce a quantitative method to set the weights of transitions, and a graphical representation of the unit that make the distinction between the definition and the realisation of the unit easier to understand.
Authors
- Jérôme Lodewyck (ORCID: https://orcid.org/0000-0003-0808-6964)
- T. Ido (ORCID: https://orcid.org/0000-0003-3500-6042)
Institutions
- Observatoire de Paris (FR)
- Laboratoire National de Métrologie et d'Essais (FR)
- Systèmes de Référence Temps-Espace (FR)
- National Institute of Information and Communications Technology (JP)
Publication Details
- Journal
- Metrologia
- Published
- 2025-09-04
- DOI
- https://doi.org/10.1088/1681-7575/ae033f
- Primary Topic
- Scientific Measurement and Uncertainty Evaluation
- Type
- article
- Field-Weighted Citation Impact
- 0.00