Research on transformation optics selected as editor's choice in New Journal of Physics

The editors of the New Journal of Physics have selected a paper by researchers from APHY and from Ames Laboratory—U.S. DOE & Iowa State University as an "editor's choice" article. The scientists from Brussels and Iowa have designed a device to achieve the seeming-impossibility of confining light to a space with dimensions smaller than its wavelength.

Confinement of light in small volumes is a key functionality required by many advanced photonic applications, such as optical information processing, optical sensing, and cavity quantum electrodynamics. A common way to achieve this is the use of optical resonators, in which light is held by internal reflection on its boundaries. However, due to the wavelike nature of light, it is impossible to efficiently confine light if the dimensions of the cavity are smaller than the wavelength.

The scientists have now developed a novel approach to design optical cavities using the geometrical technique of transformation optics. They conceived a device with walls made of metamaterials—or artificial materials with optical response not found in nature—so that the light can be made to travel in a closed curve rather than a straight line. It is demonstrated that this principle allows for the confinement of light to a space smaller than its own wavelength, while losing little energy.

These findings may have huge implications for the storage and manipulation of optical information as well as studies of the fundamental properties of light.

V. Ginis, P. Tassin, J. Danckaert, C. M. Soukoulis, and I. Veretennicoff, “Creating electromagnetic cavities using transformation optics,” New Journal of Physics 14, 033007 (2012).