Tiny electrical waves now digitally controlled
Researchers from the FOM Institute AMOLF in Amsterdam and the University of Twente have developed a way to digitally control tiny electrical waves, so-called surface plasmons. These waves play an important role in nanophotonic research, which studies materials at a very small scale. The new knowledge could lead to an interface that makes nanophotonic devices more user-friendly (comparable to Windows on a computer). The advance online publication of their work appeared yesterday in the leading journal Nature Photonics.
When light reflects off gold nanostructures under the right conditions, it creates tiny electrical waves on the surface called surface plasmon polaritons (SPPs). The researchers have now achieved SPP control in a remarkably simple and universal manner. They did this by changing the shape of the incident light with a computer-controlled megapixel device called a phase plate (similar to a liquid crystal display).
Unlike previous approaches, phase plate control is cheap and highly flexible. The researchers demonstrated this flexibility by creating a sharply focused SPP spot and scanning it across a gold surface. Such a scanned focused spot could be used to create the first super-resolution SPP microscope. In addition, the method could result in new interfaces for nanophotonic devices. This would make them more accessible for industry.
Further information
Bergin Gjonaj, +31 (0)6 50 26 11 78.
Reference
10.1038/NPHOTON.2011.57
Active spatial control of plasmonic fields
B. Gjonaj, J. Aulbach, P.M. Johnson, A.P. Mosk, L. Kuipers, A. Lagendijk