Metamaterials can strongly affect the transport properties of light in ways that are very different from the one of standard materials. Alexis Jouan works on using these metamaterials to guide sub-THz signals with low loss.

Metamaterials are mesoscopic structures which are used to guide or localize light in ways that could not be obtained with standard optical structures. The idea is to modify the materials on a typical scale much smaller than the wavelength but bigger than the lattice parameter. Because the wavelength is much longer than the periodicity of the metamaterial, the light experiences an effective medium. Condensed matter systems have inspired researchers to design original ways to guide and trap light in these mesoscopic structures.