In optical science and technology, NPL is directing research effort into science areas which are central to communications, healthcare and climate change. In support of new communication systems using quantum cryptography, NPL is developing low-photon generation systems and associated analysis tools for properties such as efficiency, polarisation and indistinguishability. A new model for predicting the performance of an optical communications link from the characteristics of its individual components including laser, fibre and detector has also been developed.

In the healthcare sector, Optical Coherence Tomography (OCT) shows great promise for carrying out non-invasive diagnostics on living tissue material. NPL is working with healthcare specialists to develop new OCT methods which will give more quantitative information on the properties of the biomaterials under investigation. Research into the measurement of fluorescence and fluorescence lifetime is also ongoing.

In sensory metrology, NPL is building on a long tradition of measurement relating to human visual perception, such as colour, and is taking these techniques into new areas such as the measurement of naturalness.

Optical radiation standards are based on radiometric techniques which equate optical to electrical power and NPL has led the world for many years in the application of cryogenic techniques to this field. New challenges in this area include accurate measurement of optical radiation in space to underpin the metrology of climate change and the measurement of temperature via radiation to establish new fixed points on the international temperature scale.

Watch a video on the candela and about measuring the quantity and quality of light.