Patrick is a Senior NPL Fellow and co-Director of the NPL Quantum Metrology Institute, concerned with state-of-the-art research into quantum frequency standards and atomic clocks and metrology. This activity combines ultra-stable laser techniques with laser-cooled ion and atom narrow reference transitions, together with high-accuracy femtosecond combs, to provide optical clocks that challenge the best available microwave atomic fountain clocks that currently define the second, and which underpin the national timescale.

The team has also developed these leading fountain clocks together with high-accuracy techniques for comparing both microwave and optical atomic clocks, both locally, and remotely by satellite and optical fibre frequency transfer. There are also R&D activities in cold atom interferometry, magnetometry and high resolution laser spectroscopy, and the development of portable microwave and optical clocks, within the team.

These microwave and optical clock technologies have wider application to fundamental physics, space science, satellite navigation and Earth observation, telecommunications, aerospace, defence and precision engineering.