An article on nano-optics by the research group led by Prof. Dr Christoph Lienau of the Institute of Physics at the University of Oldenburg, published on 12 September 2008 in the prestigious journal *Physical Review Letters*, attracted considerable international attention. The work of the Oldenburg researchers was deemed so significant and groundbreaking that it was presented to a wider audience on 16 September 2008 as a “Physical Review Focus ”. The Oldenburg group led by Dr Parinda Vasa and Lienau – in close collaboration with scientists from Germany, the USA and Korea – was able, for the first time, to analyse how light and electrons interact within nanostructures made of metals and semiconductors. “The optical properties of metallic nanostructures are currently being studied very intensively by many researchers around the world, as these structures make it possible to build a whole new class of optical microscopes and hold promise for a wide range of applications in optical metamaterials, biosensors or even cancer screening,” says Lienau. The major challenge, however, lies in storing light within metallic structures for longer periods of time.

This might possibly be achieved in composite nanostructures made of metals and semiconductors. So far, however, relatively little is known about how light and electrons interact within such complex nanostructures. Working together with the group led by Prof. Dr Gregory J. Salamo from the University of Arkansas (USA) and the group led by Prof. Dr Dai-Sik Kim from Seoul National University (South Korea), the physicists from Oldenburg have now succeeded in design and fabricate semiconductor-metal nanostructures, which have enabled this interaction to be investigated in detail for the first time. A thorough theoretical analysis of the experimental data was carried out in co-operation with the group led by Prof. Dr Erich Runge from the Technical University of Ilmenau.

Golden waves: The computer simulation shows the electric field strength in the vicinity of nanoscale gold strips (cross-sectional view) when these are irradiated with infrared light.

Kobus Kuipers from the AMOLF Institute in Amsterdam (Netherlands) praises the scientific significance of the study in *Physical Review Focus*, particularly the wide range of potential applications for the new findings. The work is regarded as an important step towards new nanolasers and could also help to develop new optical computers or improved solar cells. Sources: 1. “Lights and electrons cooperate”, Physical Review Focus, 16 September 2008
2. “Coherent Exciton-Surface-Plasmon-Polariton Interaction in Hybrid Metal-Semiconductor Nanostructures”, P. Vasa, R. Pomraenke, S. Schwieger, Yu. I. Mazur, Vas. Kunets, P. Srinivasan, E. Johnson, J. E. Kihm, D. S. Kim, E. Runge, G. Salamo, and C. Lienau. Phys. Rev. Lett. 101, 116801
Contact: Prof . Dr Christoph Lienau, Institute of Physics, Ultrafast Nano-Optics Research Group,
Tel.: 0441/798-348, email: