Electromagnetic Materials Group Opportunities

Detailed study of zigzag metal gratings
An EPSRC-funded project supporting two PhD studentships from Summer 2009
Supervisors:  Prof. Roy Sambles and Dr. Alastair Hibbins

There have been many exciting advances in photonics demonstrating that metamaterials can exhibit novel electromagnetic properties. While the term “metamaterial” has only recently been coined, perhaps the simplest example is a metallic diffraction grating. In this EPSRC funded project we wish to study zigzag gratings. These present an entirely new, and as yet completely overlooked type of metamaterial.

The research focus in the Electromagnetic Materials Group (http://www.exeter.ac.uk/physics/research/emag) in which this project will be hosted, is on the interaction between light and matter. We have a particularly strong interest in the fundamental study of electromagnetic materials that incorporate structure from the nanometre to centimetre scale.

We will use zigzag gratings, fabricated using Focussed Ion Beam techniques, to provide a mechanism for visible radiation to couple to the surface modes (surface plasmons). However, at microwave frequencies, where metals are almost perfect conductors, no bound surface waves exist. We will therefore rely on the perturbation of the surface itself to induce the necessary boundary conditions so that localised surface modes may now be supported. Coupling to both traditional surface plasmons, and the microwave equivalent, will allow for an exploration of the modes' propagation and dispersion on surfaces with novel symmetries not previously considered, including those with chiral properties. We therefore expect to observe an interesting polarisation response, with the surface able to couple both transverse magnetic and transverse electric radiation into surface modes, and potentially strong polarisation conversion from blazed gratings. We have produced a theoretical treatment for the interaction of electromagnetic radiation with such a structure, and a vital part of the project will be to develop this theory into a computer code. We will also utilise commercial numerical modelling software which will enable the researchers to study the structures from the outset.

The project offers tuition fees and a maintenance grant in accordance with Research Council eligibility criteria. Applications should include a CV, publications list, contact details for two professional referees, and should be made using the online form at http://newton.ex.ac.uk/research/phd/. Please also send a copy of your cover letter to Dr Alastair Hibbins (a.p.hibbins@ex.ac.uk), School of Physics, University of Exeter, Exeter, EX4 4QL. UK