Now showing items 1-20 of 27

    • Acoustic cloaking transformations from attainable material properties 

      Ghezzo, F; Hunt, J; Smith, David R; Urzhumov, Yaroslav A (New Journal of Physics, 2010-07-12)
      We propose a general methodology and a set of practical recipes for the construction of ultra-broadband acoustic cloaks-structures that can render themselves and a concealed object undetectable by means of acoustic scattering. ...
    • Active negative-index metamaterial powered by an electron beam 

      Alù, A; Shapiro, MA; Shvets, G; Temkin, RJ; Trendafilov, S; Urzhumov, Yaroslav A (Physical Review B - Condensed Matter and Materials Physics, 2012-08-21)
      An active negative index metamaterial that derives its gain from an electron beam is introduced. The metamaterial consists of a stack of equidistant parallel metal plates perforated by a periodic array of holes shaped as ...
    • Broadband electromagnetic cloaking with smart metamaterials. 

      Baek, S; Choi, M; Jung, Y; Kang, G; Kim, K; Park, H; Shin, D; ... (9 authors) (Nat Commun, 2012)
      The ability to render objects invisible with a cloak that fits all objects and sizes is a long-standing goal for optical devices. Invisibility devices demonstrated so far typically comprise a rigid structure wrapped around ...
    • Characterization of high order modes of plasmonic antenna formed by nanoparticle/thin film hybrid structures 

      Chen, SY; Lazarides, Alexander; Smith, David R; Urzhumov, Yaroslav A (Proceedings of SPIE - The International Society for Optical Engineering, 2012-05-04)
      The plasmonic modes of a nano-antenna formed by a nanoparticle/thin film hybrid system are investigated. Plasmonic nano-antennas are well-known for their capabilities to concentrate electromagnetic wave into extreme small ...
    • Complex k band diagrams of 3D metamaterial/photonic crystals. 

      Fietz, C; Shvets, G; Urzhumov, Yaroslav A (Opt Express, 2011-09-26)
      A finite element method (FEM) for solving a complex valued k(ω) vs. ω dispersion curve of a 3D metamaterial/photonic crystal system is presented. This 3D method is a generalization of a previously reported 2D eigenvalue ...
    • Construction of invisibility cloaks of arbitrary shape and size using planar layers of metamaterials 

      Elsen, C; Paul, O; Rahm, M; Smith, D; Urzhumov, Yaroslav A (Journal of Applied Physics, 2012-06-15)
      Transformation optics (TO) is a powerful tool for the design of electromagnetic and optical devices with novel functionality derived from the unusual properties of the transformation media. In general, the fabrication of ...
    • Cross-section comparisons of cloaks designed by transformation optical and optical conformal mapping approaches 

      Kundtz, NB; Pendry, JB; Smith, David R; Urzhumov, Yaroslav A (Journal of Optics, 2011-02-01)
      We review several approaches to optical invisibility designed using transformation optics (TO) and optical conformal mapping (CM) techniques. TO is a general framework for solving inverse scattering problems based on mimicking ...
    • Electronically reconfigurable metal-on-silicon metamaterial 

      Dhar, Sulochana; Jokerst, NM; Lee, JS; Nguyen, V; Schmalenberg, P; Smith, David R; Tyler, T; ... (8 authors) (Physical Review B - Condensed Matter and Materials Physics, 2012-08-08)
      Reconfigurable metamaterial-based apertures can play a unique role in both imaging and in beam-forming applications, where current technology relies mostly on the fabrication and integration of large detector or antenna ...
    • Enhancing imaging systems using transformation optics. 

      Kundtz, NB; Landy, Nathan I; Smith, David R; Urzhumov, Yaroslav A (Opt Express, 2010-09-27)
      We apply the transformation optical technique to modify or improve conventional refractive and gradient index optical imaging devices. In particular, when it is known that a detector will terminate the paths of rays over ...
    • Far-field analysis of axially symmetric three-dimensional directional cloaks. 

      Ciracì, Dr Cristian; Smith, David R; Urzhumov, Yaroslav A (Opt Express, 2013-04-22)
      Axisymmetric radiating and scattering structures whose rotational invariance is broken by non-axisymmetric excitations present an important class of problems in electromagnetics. For such problems, a cylindrical ...
    • Flow stabilization with active hydrodynamic cloaks 

      Smith, David R; Urzhumov, Yaroslav A (Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 2012-11-21)
      We demonstrate that fluid flow cloaking solutions, based on active hydrodynamic metamaterials, exist for two-dimensional flows past a cylinder in a wide range of Reynolds numbers (Re's), up to approximately 200. Within the ...
    • Fluid flow control with transformation media. 

      Smith, David R; Urzhumov, Yaroslav A (Phys Rev Lett, 2011-08-12)
      We introduce a new concept for the manipulation of fluid flow around three-dimensional bodies. Inspired by transformation optics, the concept is based on a mathematical idea of coordinate transformations and physically ...
    • Going beyond Axisymmetry: 2.5D Vector Electromagnetics 

      Ciracì, Dr Cristian; Landy, Nathan I; Smith, David R; Urzhumov, Yaroslav A (2012-10)
      Linear wave propagation through inhomogeneous structures of size R≫λ (Fig.1) is a computationally challenging problem, in particular when using finite element methods, due to the steep increase of the number of degrees of ...
    • Isotropic-medium three-dimensional cloaks for acoustic and electromagnetic waves 

      Landy, Nathan I; Smith, David R; Urzhumov, Yaroslav A (Journal of Applied Physics, 2012-03-01)
      We propose a generalization of the two-dimensional eikonal-limit cloak derived from a conformal transformation to three dimensions. The proposed cloak is a spherical shell composed of only isotropic media; it operates in ...
    • Leveraging nanoscale plasmonic modes to achieve reproducible enhancement of light. 

      Chen, SY; Chilkoti, A; Hill, RT; Lazarides, Alexander; Mock, JJ; Oldenburg, SJ; Sebba, DS; ... (9 authors) (Nano Lett, 2010-10-13)
      The strongly enhanced and localized optical fields that occur within the gaps between metallic nanostructures can be leveraged for a wide range of functionality in nanophotonic and optical metamaterial applications. Here, ...
    • Low-loss directional cloaks without superluminal velocity or magnetic response. 

      Smith, David R; Urzhumov, Yaroslav A (Opt Lett, 2012-11-01)
      The possibility of making an optically large (many wavelengths in diameter) object appear invisible has been a subject of many recent studies. Exact invisibility scenarios for large (relative to the wavelength) objects involve ...
    • Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances 

      Bingham, C; Chen, W; Padilla, Willie John; Smith, David R; Urzhumov, Yaroslav A (Physical Review B - Condensed Matter and Materials Physics, 2012-02-27)
      We propose that macroscopic objects built from negative-permeability metamaterials may experience resonantly enhanced magnetic force in low-frequency magnetic fields. Resonant enhancement of the time-averaged force originates ...
    • Magnetic metamaterial superlens for increased range wireless power transfer. 

      Ensworth, J; Huang, D; Lee, JS; Lipworth, G; Nomura, T; Reynolds, MS; Schmalenberg, P; ... (10 authors) (Sci Rep, 2014-01-10)
      The ability to wirelessly power electrical devices is becoming of greater urgency as a component of energy conservation and sustainability efforts. Due to health and safety concerns, most wireless power transfer (WPT) schemes ...
    • Magnetic superlens-enhanced inductive coupling for wireless power transfer 

      Hoo Teo, K; Huang, D; Smith, David R; Urzhumov, Yaroslav A; Zhang, J (Journal of Applied Physics, 2012-03-15)
      We investigate numerically the use of a negative-permeability perfect lens for enhancing wireless power transfer between two current carrying coils. The negative permeability slab serves to focus the flux generated in the ...
    • Metamaterial-enhanced coupling between magnetic dipoles for efficient wireless power transfer 

      Smith, David R; Urzhumov, Yaroslav A (Physical Review B - Condensed Matter and Materials Physics, 2011-05-18)
      Nonradiative coupling between conductive coils is a candidate mechanism for wireless energy transfer applications. In this paper we propose a power relay system based on a near-field metamaterial superlens and present a ...