The ESA mission “Space Optical Clock” project aims at operating an optical lattice clock on the ISS in approximately 2023. The scientific goals of the mission are to perform tests of fundamental physics, to enable space-assisted relativistic geodesy and to intercompare optical clocks on the ground using microwave and optical links. The performance goal of the space clock is less than 1 × 10-17 uncertainty and 1 × 10-15 τ-1/2 instability. Within an EU-FP7-funded project, a strontium optical lattice clock demonstrator has been developed. Goal performances are instability below 1 × 10-15 τ-1/2 and fractional inaccuracy 5 × 10-17. For the design of the clock, techniques and approaches suitable for later space application are used, such as modular design, diode lasers, low power consumption subunits, and compact dimensions. The Sr clock apparatus is fully operational, and the clock transition in 88Sr was observed with linewidth as small as 9 Hz.
We report on both theoretical and experimental aspects of a fully implemented quantum key distribution device
with coherent states. This system features a final key rate of more than 2 kb/s over 25 km of optical fiber. It
comprises all required elements for field operation: a compact optical setup, a fast secret bit extraction using
efficient LDPC codes, privacy amplification algorithms and a classical channel software. Both hardware and
software are operated in real time.
We report on the evaluation of an optical lattice clock using fermionic 87Sr. The measured frequency of the
1S0 → 3P0 clock transition is 429 228 004 229 873.7Hz with a fractional acuracy of 2.6 × 10-15. This evaluation
is performed on mF = ±9/2 spin-polarized atoms. This technique also enables to evaluate the value of the
differential Landé factor, 110.6Hz/G. by probing symmetrical σ-transitions.