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Geoffrey Barwood

Geoffrey Barwood

Principal scientist

Geoffrey Barwood is the Science Area Leader for the “Atomic Clocks and Sensors” group within Time and Frequency. He joined NPL after graduating from the University of Cambridge and was awarded a PhD from the University of Kent based on research undertaken at NPL. He has long experience in the development of frequency stabilised lasers using high-finesse optical cavities and using spectroscopic transitions in room-temperature molecules and cold ions both for the realisation of the metre and as optical secondary representations of the second.

Geoffrey is a co-author of over 80 peer-reviewed publications and numerous other reports, for example, 'technical notes' prepared for the European Space Agency (ESA), Dstl and also conference abstracts and presentations. His current research interests are in the development of optical and microwave frequency standards using cold trapped ion systems. This has evolved into the development of high-finesse optical cavities that are used to provide narrow-linewidth lasers for optical clocks, including applications in space. He has further expanded this area of interest into cavity-enhanced spectroscopy for trace gas detection. This uses the cavity enhanced technique of 'NICE-OHMS' for detecting trace contaminants such as ammonia, water and HCl and Geoffrey was the coordinator of the recently-completed EMPIR-funded project "MetAMCII". This consortium involves both European industrial partners and national measurement institutes.

Geoffrey is a member of the UK Institute of Physics (MInstP) and a Chartered Physicist (CPhys)

Areas of interest

  • Cold ion based optical and microwave clock development
  • Frequency stabilised lasers using high finesse optical cavities, particularly for space applications
  • Laser frequency stabilisation using spectroscopic transitions in room-temperature atoms and molecules, for example iodine, rubidium, and CO2. Recent work on CO2 has involved confining the gas within a hollow-core fibre rather than a conventional cell
  • Trace gas sensing using high finesse optical cavities and spectroscopic techniques including NICE-OHMS

Key publications

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