Precision molecular spectroscopy using a network for distribution of the Swiss primary frequency standard

• Forschungsstelle: METAS
• Projektnummer: F-5117.30110
• Projekttitel Englisch: Precision molecular spectroscopy using a network for distribution of the Swiss primary frequency standard

Schlüsselwörter (Englisch)

Primary frequency standard, optical fibre network, distribution network

Kurzbeschreibung (Englisch)

This project is part of a SNSF Sinergia project with the aim to exploit recent progress in laser technology, frequency metrology and molecule optics to carry out ultra-precise measurements of energy intervals between electronic, vibrational and rotational states of molecules, in particular molecular ions.

The targeted advancement in measurement accuracy will be enabled by the implementation of new spectroscopic methodologies based on quantum technologies, by the development of ultranarrow quantum-cascade laser sources tailored to the present needs, and in particular through the implementation of a fibre-optical network for the distribution of the Swiss primary frequency standard maintained by the Federal Institute of Metrology METAS to spectroscopy laboratories in Basel and Zurich. This network will enable the absolute stabilisation, calibration and frequency comparison of the laser sources employed in the present measurements at a level of up to 10^-15 by their referencing to the Swiss primary standard. While several European countries have already set up similar national and international networks for precision frequency distribution, Switzerland thus far possesses no such facilities. For Switzerland not to lose contact and competitiveness in the key future scientific domain of frequency metrology, it is imperative for our country to establish similar infrastructures. The present project will establish and test a prototype network connecting ETH Zurich, the University of Basel and the Federal Institute of Metrology METAS in Bern/Wabern. This prototype is intended to form the nucleus of a Swiss national network for precision frequency- and time distribution linking a broad range of national laboratories and research groups involved in frequency metrology in the future.

Projektziele (Englisch)

METAS contributes to the following objectives of the project:

Development of a strategy to distribute the Swiss primary frequency standard. The transition frequencies must be determined on an absolute scale by making comparison with the Cs-atom primary standard that is used for the definition of the second. Currently, such a standard is not available at ETH nor in Basel, nor in any Swiss research institution, but is maintained at the Federal Institute of Metrology (METAS, Wabern near Bern) in the Photonics, Time and Frequency Laboratory. Establishing a viable strategy for the broad distribution of the METAS primary frequency standard in Switzerland is urgent if the Swiss research institutions are to remain competitive with European research institutions in this field.

Development of the prototype of a distribution network for frequency standards connecting the Swiss Universities. A network for the distribution of the primary standard must be established at a reasonable cost that is compatible with the architecture of the Swiss optical-fibre networks available for telecommunication and internet. The expertise and access to the infrastructure is available from the foundation SWITCH, which provides network services to the Swiss universities and research community. Ideally, the existing network infrastructure of SWITCH is used to straightforwardly extend the distribution of the frequency standards to the whole research community and, in the middle term, to connect to the frequency-metrology networks of neighbouring countries.