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Optical Lattice

Working Group 4.32

Transportable Lattice Clocks

Transportable lattice clock with a cloud of laser-cooled strontium atoms.

Since optical atomic clocks achieve accuracies beyond the performance of primary clocks, comparisons have to be performed directly if the full accuracy is to be achieved. Comparisons of spatially separated clocks can be performed via fibre networks or using a transportable clock.

The development of transportable optical clocks is motivated not only by metrological reasons but also by fundamental research e.g. in Space. We also plan to use our transportable lattice clock for geodetic applications where the difference of two clocks’ frequencies due to their height difference (gravitational red shift) will be measured. The long term goal is to achieve a height resolution of better than 10 cm, which corresponds to a fractional uncertainty of the clock’s frequency of 10-17.

Spectrum of the strontium clock transition at 429 THz (698 nm) with a resolution of 30 Hz.