School on Optical Clocks (OCS2015)
Turin, 29 June 3 July 2015

The first School on Optical Clocks (OCS2015) will be held in Turin, Italy, from the 29th June to the 3rd July 2015. The school will be hosted by Istituto Nazionale di Ricerca Metrologica (INRIM) with the collaboration of the main European metrology institutions and the academic and industrial partners of the projects ITOC (International Timescales with Optical Clocks) and FACT (Future Atomic Clock Technology). The lectures will be held by leading experts from the European metrology institutions in the project and by invited speakers from all over the world, covering the hottest topic in frequency metrology and atomic frequency standards.
The school will be aimed at PhD students, post-docs, young scientists and engineers of the field with a strong focus on training and education.
OCS2015 is co-funded by the European Metrology Research Programme (EMRP) with the support of the European Union.

Today, the most advanced optical atomic clocks have reached levels of stability and accuracy that significantly surpass the performance of caesium primary standards, for which the best reported results are a stability of 1.4 x 10-14 τ-1/2 (where τ is the averaging time) and an accuracy of ~2x 10-16. As a result, the possibility of a future redefinition of the second in terms of an optical transition frequency is being considered by the international metrology community.

Presently, optical clocks, based on ions or on neutral atoms, exhibits an accuracy of few parts in 10 -18, and neutral lattice clocks achieve in few hours a stability ~10-18.

Optical clocks are then best candidates for a redefinition of the SI second in a close future, and they are valuable devices for fundamental physics test.

The Optical Clocks School will offer the possibility of learning the status of the art in this field. Presenting the very last results from the international community, the School will explain the efforts to ensure the reproducibility of optical clocks, coming from independent absolute frequency measurements made in different laboratories, and to achieve the remote comparison of clocks at their challenging accuracy level.

As well, the fundamental physics closely related to optical clocks will be treated, in particular the relativistic effects influencing time and frequency comparisons between optical atomic clocks at the 10-18 level of accuracy, and how to establish a connection to geodetic models in order to describe the variation of the clock frequencies due to changes in the gravity potential. On the other hand, high accuracy optical atomic clocks could have a huge impact on the field of geodesy, by using optical clocks to measure the gravity potential difference between two well-defined locations with high temporal resolution.

Finally, applications of optical clocks will be presented, as the mentioned relativistic geodesy, but also space physics and others.
In the end, the school will present the roadmap towards an International Timescale based on Optical Clocks as depicted by the EMRP project ITOC.