Chris Kelly

Chris is a PhD candidate at the University of Glasgow. His interdisciplinary project is supervised by Dr Malcolm Kadodwala (Chemistry) and Dr Donald MacLaren (Physics and Astronomy). He started his PhD in September 2016.

Project Title: Control of Chiral Metamaterial Properties with Light

A metamaterial is a material patterned with artificial elements designed to exhibit unusual electromagnetic properties, with a particular purpose in mind such as the possibility of forming a cloaking device for aircraft. In the field of optics metamaterials are created with miniscule repeating structures, often a millionth of a metre in size or smaller, which display useful properties when irradiated by light.

Each metamaterial structure can be chiral – its shape is such that it cannot be superimposed on its mirror image, much in the same way as your hands. In fact, this is the reason the pairs of mirror image chiral structures are referred to as left-handed and right-handed. When we perform spectroscopy of these structures (measuring their response to a broad frequency-range of light) we find that there can be differences in the response between the left- and right-handed structures depending on the nature of the light, or of a substance on the surface which we may wish to gather information about. This technique is called chiroptical spectroscopy and is very powerful, allowing for extremely sensitive detection of chiral molecules such as proteins and organics.

In my research, I investigate how the properties of such metamaterials can be manipulated and controlled with light, and attempt to understand their physical interactions with light and molecules on their surface. I use metamaterials made from gold which allow for sensitive detection owing to the collective electron oscillations (plasmons) at the surface, as well as more exotic materials like Europium Oxide which is fluorescent. This fluorescence can be used as a probe for changes in the metamaterial properties in order to help understand their interactions with light.