Nano-Optics

The Nanooptics Group focuses on the interaction of light with subwavelength sized structures, including nanostructures, -particles and Molecules. In particular, we investigate metal nanostructures and their optically dominating excitations, surface plasmons. For example, plasmonic nanoparticles feature resonantly enhanced and strongly localized optical fields with spectral responses that are dominated by their structure geometry. On one hand, we work on the quantumoptical foundations of plasmonic field enhancement and its femtosecond time scale dynamics. On the other hand, we apply quantum emitters as molecules or quantum dots to probe plasmonic fields through their influence on absorption and emission dynamics, opening a window into the dynamics of simple quantum systems. In addition we investigate plasmonic waveguides that are not limited by diffraction and can thus be of nanoscale cross section. Complementing our basic research we develop applications of nanooptical systems for biosensing and for increasing the efficiencies of light sources and detectors.

The Nanooptics Group is nevertheless strongly involved in collaborations in terms of modeling and simulation. Nanoscale optics deals with size dimensions where both conventional bulk and dipolar approximations fail, calling for calling for numerical methods for a full proper description. A long lasting fruitful collaboration exists with the Theoretical Solid State Group (Ulrich Hohenester) that provides the theory frame for plasmonic nanostructures and their coupling to quantum emitters as well as to electrons. We work as well closely together with international theory groups and provide significant input with experimental validation and by providing material parameters. Furthermore, we constantly apply homebuilt as well as commercial software tools as an important part of our work.

Contact: Joachim Krenn