Metallic nanorings with diameters smaller than 100 nm show plasmonic resonances which result in a wide range of color effects. These resonances rely on coherent oscillations of the conduction electrons and range down to the visual spectral range. The form of these resonances is controlled by well-designed structuring.
The rings are created with electron beam lithography. They can be realized with little effort by choosing suitable etching and metallization technologies.
It is possible to further reduce this effort by changing the type of lithography. For this, block copolymer nanolithography, based on self-organization processes, is used.
The process developed enables the allocation of nanomaterials for research and industrial applications (color filters for sensors).
Other geometries will be created in the future to enable the construction of more complex metamaterials, such as negative index materials. The process will be further developed to make volume materials available.