Background of the Research Program of the ITN

Research in the fields of precision spectroscopy, quantum optics and cold atoms, honored by the Physics Nobel Prizes 1989, 1997, 2001, 2005 and 2012 has triggered a new era in precision measurements and quantum metrology. One eminent example of new instrument is the optical atomic clock. Atomic clocks operating at microwave frequencies are well-established and have already shown their usefulness in a variety of application, especially for satellite-based navigation (GPS, GLONASS, Galileo) and in communication networks.

In optical atomic clocks it is a (laser) electromagnetic wave that “ticks”. However it beats 1015 times per second instead of 1010 as in microwave clocks. The progress in the performance of laboratory prototypes has been spectacular - the best inaccuracy and best instability are now both smaller than 1×10-17 and still progressing, thanks to world-wide efforts. While these instruments will surely have many applications, a few are already emerging: geodesy (measurement of the gravitational potential of the Earth) and tests of fundamental physics.

So far, optical clocks are mainly confined to a handful of advanced labs and it is important to develop robust system for general use and in particular also for applications in space.

This ITN addresses all of the issues in moving towards space optical clocks by covering every aspect ranging from atomic references and ultra-stable lasers to frequency combs, precision frequency distribution and commercial system technology. It focuses on technological developments enhancing the technology readiness level of the new optical atomic clocks, enhancing the chance that they will become industrially produced instruments.

FACT benefits from links to the EU-FP7 project “Space Optical Clocks” and the ESA candidate mission “SOC”, a lattice optical clock on the ISS (, which provides resources for the respective technology developments and offers exposure of the ERS group to the field of space technology. The space industry side is also represented by our partner companies Kayser Threde and Kayser Italia.

FACT will prepare a new generation of young experts in precision atomic technology.

Specific S&T Objectives

FACT focuses on a substantial increase in the technological readiness level of the emerging optical clocks and frequency standards. While currently driven by the drive towards space, the ultimate aim of this ITN is to arrive at the point where commercial development activities can take over, building also on the human resource of experts trained along the way. To achieve this aim a range of robust technologies will be developed, covering all aspects of an optical clock instrument.

FACT has the following central science and technology objectives (SO):
SO1: To overcome the technology bottleneck in bringing cold atom systems to market applications and demonstrate a mobile optical frequency standard.
SO2: To develop the technology for a robust laser with sub-Hz linewidth as “optical flywheel”.
SO3: To foster technology making the superior performance of optical clocks available to end users and applications.
SO4: To demonstrate feasibility with a commercial concept for an optical clock system.

State-of-the Art, Originality, Coherency and Innovative Aspects of the FACT ITN

Fundamental science, technology and innovation are inseparable. The programme FACT is an excellent example as it imbibes all the three in the same way. Athough it is driven by technology and innovation, it helps address questions related to fundamental science at the forefront, for example “relativistic geodesy”, variation of fundamental constants etc. While the field of ultra cold atoms in a very short span of time has laid down an excellent base of fundamental knowledge to a novel level, research on quantum ICT based on ultra cold atoms very much remains confined to very few advanced laboratories.
The idea of FACT is to utilise this base for a greater exploitation including space as well as industry. FACT’s technological and innovative aspect emphasises on mobility, compactness, robustness, modular nature, miniaturised and integrated, and space compatible systems.
Space is an attractive avenue due to a number of reasons among which one is the multifold increment in the sensitivity of a sensor. In fact, with the continuous push on technology, space is becoming more and more viable and attractive destination. Advanced mobile optical clocks with ultra high precision are a big step forward in this direction. Transportable cold Cs microwave clock with instability 1.2×10-131/2 and inaccuracy 6.6×10-13 [Biz09] developed by the team member OP in Paris laid the foundation for transportable precision measurements and quantum metrology, and in general for ultra cold atom based ultra precise quantum sensors. This transportable clock has also been an important prototype for the development of the space clock PHARAO [Cac09]. It has been transported to several European laboratories to serve as a frequency standard, in absence of or for the purpose of calibrating a local frequency standard.

Similar applications are foreseen for transportable optical clocks, but at higher accuracy level. In particular, the mentioned candidate space mission “SOC” targets operation of a high-performance lattice optical clock on the ISS for fundamental physics and Earth science in approx. 2019. The specification of the lattice clock is an instability and an uncertainty of 1×10-17.

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[Biz09] S. Bize et al. “Réalisation et diffusion de la seconde au LNE-SYRTE”, Revue Française de Métrologie, 18, 13 (2009); S. Bize et al. “Cold atom clocks and applications” J. Phys. B: At. Mol. Opt. Phys, 38, S449-468 (2005)
[Cac09] L. Cacciapuoti and Ch. Salomon,“Space clocks and fundamental tests: The ACES Experiment”, Eur. Phys. J. Special Topics 172, 57–68 (2009)

background.txt · Last modified: 2016/02/18 15:22 by ur