The interaction of light with surface plasmons — collective oscillations of free electrons — in metallic nanostructures leads to novel optical phenomena. These structures typically consist of ordered arrays of particles or holes with sizes of the order of 100 nm. However, surface plasmons can interact with each other over much longer distances, so the ability to organize nanoscale particles or holes over multiple length scales could lead to new plasmonic metamaterials. We have developed a new nanofabrication technique — soft interference lithography — to produce such metamaterials. These structures include various infinite and finite-area arrays of nanoholes and nanoparticles as well as patterns that contain both metallic and dielectric materials. The free-standing gold film of nanoholes shown on the cover demonstrates the hierachical patterning capabilities of soft interference lithography.
