Quantum Optics Seminar by Rodolphe Le Targat

International strontium optical lattice clocks comparisons with an optical fiber link 

Optical Lattice Clocks (OLCs) have progressed rapidly in the last years:systematic uncertainties in the 10^-18 range were reported, and no fundamental limit has been identified so far. In the context of possible future frequency standards based on an optical transition, the next challenge is the assessment of the reliability and the reproducibility in the long run of this new generation of clocks. 

To circumvent the limitations of satellite-based frequency comparisons, PTB (Germany) and SYRTE (France) have developed an intercontinental 1415 km fiber link to connect the two institutes.This link stability is 10^-18 after 1000 seconds, thus allowing us to take full benefit of the stability of our optical lattice clocks. 

In this presentation, I will describe the different systems and show the results of the first measurement campaigns of 2015, which led to the demonstration of the agreement between two Sr lattice clocks located at SYRTE and at PTB, with an overall uncertainty of 5x10^-17. I will discuss the limit of the system as well as its scalability.