85 research outputs found

    Comment on "Far-field microscopy with a nanometer-scale resolution based on the in-plane image magnification by surface plasmon polaritons"

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    This is a small comment concerning the work by Smolyaninov et al. in Phys. Rev. Lett.94, 057401 (2005)

    An ultraviolet simulator for the incident Martian surface radiation and its applications

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    Ultraviolet (UV) radiation can act on putative organic/biological matter at the Martian surface in several ways. Only absorbed, but not transmitted or reflected, radiation energy can be photo-chemically effective. The most important biological UV effects are due to photochemical reactions in nucleic acids, DNA or RNA, which constitute the genetic material of all cellular organisms and viruses. Protein or lipid effects generally play a minor role, but they are also relevant in some cases. UV radiation can induce wavelengths-specific types of DNA damage. At the same time it can also induce the photo-reversion reaction of a UV induced DNA photoproduct of nucleic acid bases, the pyrimidine dimers. Intense UVB and UVC radiation, experienced on early Earth and present-day Mars, has been revealed to be harmful to all organisms, including extremophile bacteria and spores. Moreover, the formation of oxidants, catalytically produced in the Martian environment through UV irradiation, may be responsible for the destruction of organic matter on Mars. Following this, more laboratory simulations are vital in order to investigate and understand UV effects on organic matter in the case of Mars. We have designed a radiation apparatus that simulates the anticipated Martian UV surface spectrum between 200 and 400 nm (UVC-UVA). The system comprises a UV enhanced xenon arc lamp, special filter-sets and mirrors to simulate the effects of the Martian atmospheric column and dust loading. We describe the technical setup and performance of the system and discuss its uses for different applications. The design is focused on portability, therefore, the Mars-UV simulator represents a device for several different Mars simulation facilities with specific emphasis on Mars research topics

    Cooperative coupling of ultracold atoms and surface plasmons

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    Cooperative coupling between optical emitters and light fields is one of the outstanding goals in quantum technology. It is both fundamentally interesting for the extraordinary radiation properties of the participating emitters and has many potential applications in photonics. While this goal has been achieved using high-finesse optical cavities, cavity-free approaches that are broadband and easy to build have attracted much attention recently. Here we demonstrate cooperative coupling of ultracold atoms with surface plasmons propagating on a plane gold surface. While the atoms are moving towards the surface they are excited by an external laser pulse. Excited surface plasmons are detected via leakage radiation into the substrate of the gold layer. A maximum Purcell factor of ηP=4.9\eta_\mathrm{P}=4.9 is reached at an optimum distance of z=250 nmz=250~\mathrm{nm} from the surface. The coupling leads to the observation of a Fano-like resonance in the spectrum.Comment: 9 pages, 4 figure

    Surface Plasmon mediated near-field imaging and optical addressing in nanoscience

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    We present an overview of recent progress in plasmonics. We focus our study on the observation and excitation of surface plasmon polaritons (SPPs) with optical near-field microscopy. We discuss in particular recent applications of photon scanning tunnelling microscope (PSTM) for imaging of SPP propagating in metal and dielectric wave guides. We show how near-field scanning optical microscopy (NSOM) can be used to optically and actively address remotely nano-objects such as quantum dots. Additionally we compare results obtained with near-field microscopy to those obtained with other optical far-field methods of analysis such as leakage radiation microscopy (LRM)

    Plasmonic Luneburg and Eaton Lenses

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    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.Comment: Accepted for publication in Nature Nanotechnolog

    Plasmon polaritons of metallic nanowires for controlling submicron propagation of light

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    Abstract: The optical resonances of individual plasmonic dimer antennas are investigated using confocal darkfield spectroscopy. Experiments on an array of antennas with varying arm lengths and interparticle gap sizes show large spectral shifts of the plasmon modes due to a combination of geometrical resonances and plasmon hybridization. The resonances of the coupled-dimer antennas are considerably broadened compared to those of single nanorods, which is attributed to a superradiant damping of the coupled antenna modes. The scattering spectra are compared with electrodynamic model calculations that demonstrate both the near-field and far-field characteristics of a half-wave antenna

    Nanostructured glass fibres for optical trapping of nanoparticles

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    We introduce metal coated and nanostructured optical fibres for nanoparticle trapping. Information is provided on the probe manufacturing and design, with the distribution of the optical forces simulated with the finite element method
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