2011/01/13 by Thomas Zentgraf, Yongmin Liu, Maiken H. Mikkelsen +2 · 4 citations
Engineering · Materials Science · Physics and Astronomy · #Metamaterials and Metasurfaces Applications #Plasmonic and Surface Plasmon Research #Thermal Radiation and Cooling Technologies #physics.optics
paper · pdf · doi:10.1038/nnano.2010.282
Accepted for publication in Nature Nanotechnology
arxiv created 2011/01/13 · arxiv updated 2011/01/14 · crossref issued 2011/01/23 · crossref published 2011/01/23 · crossref published-online 2011/01/23 · openalex publication_date 2011/01/23 · crossref created 2011/01/23 · crossref published-print 2011/03/01 · crossref deposited 2023/05/19 · openalex created_date 2025/10/10 · crossref indexed 2026/06/09 · openalex updated_date 2026/07/29
Plasmonics is an interdisciplinary field focusing on the unique properties of both localized and propagating surface plasmon polaritons (SPPs) - quasiparticles in which photons are coupled to the quasi-free electrons of metals. In particular, it allows for confining light in dimensions smaller than the wavelength of photons in free space, and makes it possible to match the different length scales associated with photonics and electronics in a single nanoscale device. Broad applications of plasmonics have been realized including biological sensing, sub-diffraction-limit imaging, focusing and lithography, and nano optical circuitry. Plasmonics-based optical elements such as waveguides, lenses, beam splitters and reflectors have been implemented by structuring metal surfaces or placing dielectric structures on metals, aiming to manipulate the two-dimensional surface plasmon waves. However, the abrupt discontinuities in the material properties or geometries of these elements lead to increased scattering of SPPs, which significantly reduces the efficiency of these components. Transformation optics provides an unprecedented approach to route light at will by spatially varying the optical properties of a material. Here, motivated by this approach, we use grey-scale lithography to adiabatically tailor the topology of a dielectric layer adjacent to a metal surface to demonstrate a plasmonic Luneburg lens that can focus SPPs. We also realize a plasmonic Eaton lens that can bend SPPs. Since the optical properties are changed gradually rather than abruptly in these lenses, losses due to scattering can be significantly reduced in comparison with previously reported plasmonic elements.