Nanoplasmonics: New design concepts for nanoscale optical cavities

The design of nanoplasmonic cavities exploiting coherent processes such as sub- and superradiance as well as Fano-type interactions will be discussed, under the framework of plasmon hybridization theory. In such cavities, interactions between bright and dark localized plasmon modes lead to a complex mode spectrum, which can be visualized using electron energy loss spectroscopy. First implementations fabricated using electron beam lithography will be presented. Furthermore, it will be shown how the concept of transformation optics can be utilized for the design of nanoresonators with a broadband absorption spectrum, showing high promise for light harvesting over the whole visible and infrared range of the spectrum.