Browsing by Author "Smith, DR"
Now showing items 1-20 of 20
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Acoustic cloaking transformations from attainable material properties
(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. ... -
Analysis of the power dependent tuning of a varactor-loaded metamaterial at microwave frequencies
(Applied Physics Letters, 2010-03-26)We present an analysis of the nonlinear, power-dependent resonance frequency shift for two metamaterial mediums consisting of arrays of varactor-loaded split ring resonators (VLSRRs). We confirm that, over a limited range ... -
Analytic expressions for the constitutive parameters of magnetoelectric metamaterials
(Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 2010-03-17)Electromagnetic metamaterials are artificially structured media typically composed of arrays of resonant electromagnetic circuits, the dimension and spacing of which are considerably smaller than the free-space wavelengths ... -
Characterization of high order modes of plasmonic antenna formed by nanoparticle/thin film hybrid structures
(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 ... -
Cross-section comparisons of cloaks designed by transformation optical and optical conformal mapping approaches
(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 ... -
Designing three-dimensional transformation optical media using quasiconformal coordinate transformations.
(Phys Rev Lett, 2010-11-05)We introduce an approach to the design of three-dimensional transformation optical (TO) media based on a generalized quasiconformal mapping approach. The generalized quasiconformal TO (QCTO) approach enables the design of ... -
Electronically reconfigurable metal-on-silicon metamaterial
(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 ... -
Experimental determination of the quadratic nonlinear magnetic susceptibility of a varactor-loaded split ring resonator metamaterial
(Applied Physics Letters, 2010-07-05)This letter presents a quantitative measurement of the second harmonic generated by a slab of varactor loaded split ring resonator metamaterial and the retrieval of the effective quadratic nonlinear magnetic susceptibility ... -
Going beyond Axisymmetry: 2.5D Vector Electromagnetics
(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
(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 ... -
Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances
(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 superlens-enhanced inductive coupling for wireless power transfer
(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
(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 ... -
Nanophotonics: Optical time reversal with graphene
(2013-07)Would you ever guess that a microscopic flake of graphite could reverse the diffraction of light? An experiment that demonstrates just such an effect highlights the exciting optical applications of graphene — an atomic layer ... -
Nonlinear long-range plasmonic waveguides
(Physical Review A - Atomic, Molecular, and Optical Physics, 2010-09-13)We report on plasmonic waveguides made of a thin metal stripe surrounded on one or both sides by a Kerr nonlinear medium. Using an iterative numerical method, we investigate the stationary long-range plasmons that exist ... -
Nonlinear oscillator metamaterial model: numerical and experimental verification.
(Opt Express, 2011-04-25)We verify numerically and experimentally the accuracy of an analytical model used to derive the effective nonlinear susceptibilities of a varactor-loaded split ring resonator (VLSRR) magnetic medium. For the numerical validation, ... -
Probing the ultimate limits of plasmonic enhancement.
(Science, 2012-08-31)Metals support surface plasmons at optical wavelengths and have the ability to localize light to subwavelength regions. The field enhancements that occur in these regions set the ultimate limitations on a wide range of nonlinear ... -
Relaxation approach for the generation of inhomogeneous distributions of uniformly sized particles
(Applied Physics Letters, 2010-07-12)For many applications in gradient index devices and photonic crystals, it is necessary to be able to design semicrystalline distributions of particles where the lattice constant of the distribution is an arbitrary function ... -
Structurally Rigid Elastic Composites for Acoustic Imaging Countermeasures
(2013-06-07)We explore the possibilities coming from transformation acoustics and beyond for creating rigid elastic composite shells capable of suppressing the total scattering cross-section of acoustically large objects. The reported ... -
Towards macroscopic optical invisibility devices: geometrical optics of complex materials
(2012-01-18)Recently, a path towards macroscopic, transparent optical cloaking devices that may conceal objects spanning millions of wavelengths has been proposed [1]. Such devices are designed using transformation optics (TO) [2,3]. ...
