NPL is developing both lab-based and transportable cold atom and ion clocks
with optical clock accuracies in the region of a few parts in 1018.
We have also developed and patented a novel vibration-insensitive
space-deployable cubic optical reference cavity for ultra-stable lasers. The group will shortly install a ground-based
microwave link terminal at NPL, for communication with the Atomic Clock Ensemble
in Space (ACES) due for launch to the international space station within the
next year. This will be one of seven terminals worldwide, allowing highest
accuracy clock comparisons by satellite between several international metrology
institutes.