High-accuracy time measurement for optical atomic clocks
Accurate global timekeeping is based on the use of a worldwide standard definition of the second, the SI base unit of time. The second is currently best realised using caesium fountain atomic clocks, but optical atomic clocks can measure time with even greater accuracy. However, many previous demonstrations of optical atomic clock performance have been based on estimates, not experimental verification. This project will build on the achievements of EMRP projects SIB04 Ion Clock and SIB55 ITOC and help to unlock the potential of these clocks by developing measurement techniques that can verify accuracy to one billionth of a billionth of a second, one hundred times more accurately than caesium clocks. The ability to measure time to such a degree of accuracy will support the use of optical atomic clocks in the definition and proposed redefinition of the second, and will find application in a broad range of scientific and commercial arenas, from aiding in the search for dark matter to improving the service from global navigation satellite systems.