We use light to link molecules together in new ways.

(this picture in September 2020 was of our first ‘face-to-face’ meeting since March 2020)


Molecules that harness light are all around us, whether as smart phone display screens or as leaves on plants


Traditionally, making molecules with new properties, e.g. dyes of different colours, has been the province of chemistry, new properties are based on making new molecules. Our approach is fundamentally different, we use light to alter the way molecules interact with each other, something that can lead to radical changes in their properties, without changing their chemical composition. We use two related techniques known as strong coupling and weak coupling.

Perhaps most amazingly the light we used is not ‘real’, instead we harness the power of quantum optical fluctuations in the vacuum, so-called ‘virtual’ light. We are looking at how this approach might be used to change the way molecular materials transport energy, modify chemical reaction rates, and guide light. This research project is hosted by the University of Exeter and funded primarily by Europe through an ERC AdG award to Prof. Bill Barnes.

Strong Coupling

Strong coupling of molecules with light leads to two remarkable features: modified energy levels and the delocalization of energy. Strong coupling may enable the creation of an entirely new class of materials.

Weak Coupling

Nanophotonics involves manipulating light on length scales much smaller than the wavelength of the light, i.e., much smaller than the world’s best microscopes achieve, even the new generation of super-resolution microscopes.

This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 742222).