Bulletin of the American Physical Society
2009 APS March Meeting
Volume 54, Number 1
Monday–Friday, March 16–20, 2009; Pittsburgh, Pennsylvania
Session B27: Plasmonics and Metamaterials |
Hide Abstracts |
Sponsoring Units: FIAP Chair: Harry Atwater, California Institute of Technology, Chris Van de Walle, University of California, Santa Barbara Room: 329 |
Monday, March 16, 2009 11:15AM - 11:27AM |
B27.00001: Controlling electric fields spatially by graded metamaterials Kin-Wah Yu The local electric field of a metal-dielectric composite cylinder, whose complex permittivity is given by a spatially dependent Drude model, has been derived analytically in terms of hypergeometric functions. Our results show that the electric field inside the cylinder can be confined to any desired position. Thus one can achieve the control of electric fields by fabricating graded metamaterials with specific material parameters. The enhanced nonlinear optical response of the composite cylinder has also been calculated [1]. The results suggest that the gradation-controlled electric field distribution may be a consequence of a combination of surface plasmon resonance and the microgeometry in graded metamaterials. Moreover, such a gradation-controlled field distribution serves as a physical mechanism for understanding the enhanced nonlinear optical responses with a broad surface plasmon band [2]. \\[3pt] [1] J. P. Huang and K. W. Yu, Phys. Rep. {\bf 431}, 87 (2006).\\[0pt] [2] J. P. Huang and K. W. Yu, Appl. Phys. Lett. {\bf 85}, 94 (2004). [Preview Abstract] |
Monday, March 16, 2009 11:27AM - 11:39AM |
B27.00002: Terahertz nanogap antenna detection of nano-bridges and nano-rods H.R. Park, M.A. Seo, J.S. Kyoung, S.M. Koo, O.K. Suwal, S.S. Choi, N.K. Park, D.S. Kim We have measured transmission properties of a composite structure consisting of nano-rods on a long (a$_{y}$=300 micron) nano gap (70 nm) on Au film in broad frequency range of 0.1 THz to 1.0 THz using THz time-domain spectroscopy. The normalized transmittance with no nano-bridge or nanorod structure in the middle shows a half-wavelength resonance: the resonance frequency is $\sim c$/(2\textit{na}$_{y})$ where $n$ is the index of refraction of the substrate. The nano-size bridge at the center of the nano gap gives changes the resonance characteristics profoundly, because in essence, the length a$_{y}$ now halves. Mostly the same resonance-changing behavior is expected with a nano rod structure fabricated by Pt-deposition method using a focused ion beam (FIB). This small rod also acts as a bridge dividing the length of the rectangle. We also positioned nano-rods to lie at one third of each nano gap, dividing the length by the ratio of 1: 2. A resonance peak shift was observed. The structure dependent resonance allows to detect nano-size particles and to tailor resonance characteristics with feature sizes of \textit{$\lambda $}/10,000. [Preview Abstract] |
Monday, March 16, 2009 11:39AM - 11:51AM |
B27.00003: Terahertz Nanogap Plasmonics: Giant Field Enhancement M. A. Seo, H. R. Park, S. M. Koo, O. K. Suwal, S. S. Choi, N. K. Park, D. S. Kim We show that a nanogap dividing two conducting planes can efficiently transmit terahertz electromagnetic waves with wavelengths in the millimeter range. Terahertz time domain spectroscopy is performed to probe transmittance over a frequency range of 0.1 THz to 1.5 THz. It was found that the transmittance continues to increase as the frequency decreases with a dependence of 1/f. The area-normalized transmittance, which is equivalent to the level of field enhancement, reaches the value of 800 at 0.1 THz for a sample with a 70 nm gap. Combined with the 1/f dependence, this indicates that strong local resonance is not a prerequisite for a large field enhancement. It is shown that the accumulation of charges at metal edges via light-induced currents creates a large horizontal electric field, which in effect attracts the incoming light. The enhanced field in the gap fully scatters towards the far-field because there exists no cut-off. With the broad 1/f spectral response, this structure can be an excellent launching pad for inducing terahertz nonlinearity, nano-particle detection, and for surface enhanced Raman scattering. [Preview Abstract] |
Monday, March 16, 2009 11:51AM - 12:03PM |
B27.00004: Active Control of Propagating Surface Plasmons Excited by a Quantum Cascade Laser Daniel Wasserman, Troy Ribaudo, Eric Shaner, Scott Howard, Fow-Sen Choa, Claire Gmachl There has been significant interest, of late, in the optical properties of subwavelength features in metallic films. For instance, resonant transmission through periodic arrays of subwavelength apertures in metallic films is seen at wavelengths determined by the periodicity of the metal film and the relative permittivity of the metal and the surrounding dielectric medium. This phenomenon is referred to as extraordinary optical transmission (EOT) and has been studied for potential applications in display and sensing technologies. Here we demonstrate the ability of an actively tunable EOT grating to control the coupling of incident coherent radiation from a dual wavelength QCL to propagating surface modes on the grating. We use a novel spatially and spectrally resolved Fourier transform infrared spectroscopy technique to image the propagating surface waves on our EOT grating, and are able to extract a plasmon propagation length from the data collected. [Preview Abstract] |
Monday, March 16, 2009 12:03PM - 12:15PM |
B27.00005: Spatial and Spectral Investigation of Extraordinary Optical Transmission T. Ribaudo, B.S. Passmore, E.A. Shaner, D. Wasserman Extraordinary Optical Transmission (EOT), or the enhancement of light transmission through periodic arrays of sub-wavelength holes in metal films, has been investigated for its clear contradiction with conventional aperture theory, as well as for possible applications in chemical sensing and display technologies. In the visible and near-infrared spectral ranges, EOT is argued to be predominantly a result of the excitation of surface plasmon polaritons (SPPs) on metal/dielectric interfaces. Here, we report our investigations of the far-field transmission characteristics of EOT gratings designed for the mid-infrared frequency range. Using a tunable Quantum Cascade Laser, we explore the spatial and spectral dependence of the transmitted far field on the angle of incidence and the exciting frequency of the laser. We show that for frequencies coincident with the EOT maximum, little SPP propagation is observed, while laser frequencies on the high energy falling edge of the EOT peak couple to such propagating modes. [Preview Abstract] |
Monday, March 16, 2009 12:15PM - 12:27PM |
B27.00006: Mid Infrared Beam Steering Using Plasmonic Structures David Adams, Daniel Wasserman The interaction of electromagnetic radiation with periodic features on metal surfaces has received a great deal of attention in recent years. The far-field transmission properties of a sub-wavelength aperture can be controlled when periodic grooves are formed on the exit surface, allowing the shape and directionality of the transmitted beam to be altered. This phenomenon is a result of surface plasmon polaritons propagating along the metal surface and recoupling to photons which are phase mismatched with respect to the transmitted beam. The resulting interference pattern is dependent on the wavelength of the exciting beam, the geometry of the periodic surface structure, and the dielectric permittivity of the materials at the boundary. Here we present simulations using finite element analysis which demonstrate the steering of the beam transmitted through the metal slit as the permittivity of the surrounding material is modified. [Preview Abstract] |
Monday, March 16, 2009 12:27PM - 12:39PM |
B27.00007: Extraordinary Optical Absorption through Plasmonic Subwavelength Slits Justin White, Georgios Veronis, Zongfu Yu, Edward Barnard, Anu Chandran, Shanhui Fan, Mark Brongersma We report on the ability of resonant plasmonic slits to efficiently concentrate electromagnetic energy into a nanoscale volume of absorbing material placed inside or right behind the slit. This gives rise to extraordinary optical absorption (EOA) characterized by an absorption enhancement factor that well-exceeds the enhancements seen for extraordinary optical transmission (EOT) through slits. A semi-analytic Fabry-Perot model for the resonant absorption is developed and shown to quantitatively agree with full-field simulations. We show that absorption enhancements of nearly 1000\% can be realized at 633nm for slits in aluminum films filled with silicon. This effect can be utilized in a wide range of applications, including high speed photodetectors, optical lithography and recording, and biosensors. [Preview Abstract] |
Monday, March 16, 2009 12:39PM - 12:51PM |
B27.00008: Birefringence in Ring Resonator by Free Spectral Range and Wavelength measurement. Chooda Khanal, Magdalena Nawrocka, Xuan Wang, Tao Liu, Roberto Panepucci The spectrum of coupled light through a 10 {\_}m diameter silicon-on-insulator ring resonator from a 1280-1620nm band tunable laser source is investigated. A wavelength dependent group index is calculated by measuring the Free Spectral Range of TM and TE modes. Group index for TM mode decreases with the increase in wavelength while that for TE modes increases slowly in the given wavelength range. Our preliminary data shows that the group index birefringence is almost 0.5 at the lower wavelength band. Moreover, analysis of FWHM, power dependence and dispersion will be presented with wavelength routing applications discussed. [Preview Abstract] |
Monday, March 16, 2009 12:51PM - 1:03PM |
B27.00009: Optical Vortexed Transmission through a Nanoslit on the Pyramid Seong Soo Choi, M.J. Park, N.K. Park, D.S. Kim The nanoslit apertures with its gap ranging from 1 nm to $\sim $ 50 nm have been fabricated using microfabrication process such as wet etching, thermal oxidation, circular aperture opening by HF, then followed by Al metal deposition. The light transmission through the single nanoslit apertures has been measured to be dependent upon the gap between two metal edges and independent of length of the slit. With decreasing the gap from 80 nm to 1 nm, the optical transmission rate has been increased upto three order of magnitude. This can be attributed to optical vortexed transmission [Preview Abstract] |
Monday, March 16, 2009 1:03PM - 1:15PM |
B27.00010: Visible Far-Field Superlens for Two-Dimensional Imaging Below the Diffraction Limit Emily Ray, Rene Lopez Retaining the information carried by evanescent waves scattered from an object could allow for imaging features below the diffraction limit without time consuming scanning procedures. We show experimental results of sub-diffraction limited imaging with visible light using a metal and dielectric multilayer structure with a 2-D diffraction grating. The multilayer structure has an effective negative index of refraction that enhances evanescent waves. Interaction with the diffraction grating converts waves from evanescent into propagating, enabling collection with conventional optics. We are able to tune this far-field superlens (FSL) to our choice of operating wavelengths by modulating the thickness of the metal and dielectric layers. For a wavelength of 532 nm, we use Ag and Al$_{2}$O$_{3}$ layers with 20 nm thickness to image features with 150 nm size. This FSL functions with visible light to amplify evanescent waves and recreate images below the diffraction limit. [Preview Abstract] |
Monday, March 16, 2009 1:15PM - 1:27PM |
B27.00011: Field dependent enhancement of the magneto-optical Kerr effect by surface plasmon resonance C. Clavero, K. Yang, J.R. Skuza, R.A. Lukaszew Surface Plasmon Resonance (SPR) is of interest in a variety of applications ranging from bio-sensing to optical communications. In bio-sensing, the high sensitivity of SPR to changes in the dielectric constant at the metal-dielectric interface is used to detect specific molecular bindings. We have studied the effect of adding ferromagnetic materials to Au films and we have found a remarkable enhancement of the magneto-optical Kerr effect in Au-Co-Au trilayers when SPR is excited$^{1}$. This large enhancement is ascribed to the increase of the electromagnetic field within the Co film due to the excitation of SPR, and has been modeled for ultrathin Co films$^{2}$. At resonance the electromagnetic field within the Au-Co-Au trilayer decays exponentially with the distance from the Au-air interface where the SPPs are propagating. In order to probe the influence of the electromagnetic field within the Co film on its magneto-optical response, Au-Co-Au trilayers with the Co film positioned at different distances from the Au-air interface, while keeping the thickness of all the layers constant where prepared using sputtering deposition in ultra-high vacuum conditions. Our latest results will be presented and differences with proposed model will be discussed. 1. V. I. Safarov et al., Phys. Rev. Lett. \textbf{73}, 3584. 2. C. Hermann \textit{et al}., Phys. Rev. B \textbf{64}, 235422. [Preview Abstract] |
Monday, March 16, 2009 1:27PM - 1:39PM |
B27.00012: Manipulating, Extending, and Re-Routing Optical Near Fields Using Epsilon-Near-Zero Metamaterials in Nano-Optics Nader Engheta, Andrea Alu In recent years, we have developed the notion of lumped optical circuit nanoelements as building blocks for the design of nanoscale systems and components in nano-optics. In this context, we have also introduced the concept of an optical ``nanocircuit board,'' based on epsilon-near-zero (ENZ) metamaterials. Using analytical methods and full-wave numerical simulations, we show here that optical fields in the near field of a source may be efficiently manipulated, ``extended,'' and re-routed in arbitrarily-shaped air grooves carved in ENZ metamaterial substrates, that may effectively act as optical ``wires'' connecting different elements with essentially no phase variation. Such substrates may be obtained by using natural materials with the real part of permittivity near zero, e.g., SiC near 10.3 micron wavelength, or using layered stacks of epsilon-negative (e.g., metal) and epsilon-positive (e.g., dielectric) thin layers in the visible domain, for which the effective bulk substrate may exhibit epsilon-near-zero (ENZ) properties at certain wavelength regimes for transversally polarized electric field. In this talk, we will discuss some of the exciting features of such nano-optical structures for near-field manipulation, re-routing and extension. [Preview Abstract] |
Monday, March 16, 2009 1:39PM - 1:51PM |
B27.00013: Symmetry and degeneracy in metamaterial trimers Chih-Wei Chang, Ming Liu, Sunghyun Nam, Shuang Zhang, Guy Bartal, Xiang Zhang Metamaterial trimers consist of three-coupled split-ring resonators with alternative signs of nearest-neighbor couplings are designed and fabricated. Experimental results from Fourier transform infrared spectroscopy measurements are compared with those of metamaterial dimers. We demonstrate that metamaterial trimers exhibit two-fold degenerate magnetic resonances at infrared frequencies. Remarkably, the degeneracy originates from a new kind of topological symmetry that does not exist in natural materials. [Preview Abstract] |
Monday, March 16, 2009 1:51PM - 2:03PM |
B27.00014: Composite Metal-Semiconductor Metamaterials with Negative Permittivity and No Loss A.M. Bratkovsky, E.V. Ponizovskaya, S-Y. Wang, P. Holmstrom, L. Thylen Close to the resonance in a planar interface between a metal and dielectric, where $\varepsilon _{metal} \quad \approx -\varepsilon _{dielectric}$, very tight electromagnetic field confinement results, but the tighter the confinement, invariably, the higher the propagation losses. For confinement significantly better than that of Si nanowires ($\sim $300 nm) propagation losses become prohibitively high for most interconnect applications. Also, the magnitude of $\varepsilon _{metal}$ needs to be larger than e.g. 2 in order to interface to common dielectrics for close to resonance conditions. The most straightforward way to alleviate this situation is of course to use optical gain. We have analyzed theoretically a metamaterial, which is a mix of quantum dots (QDs) half of them pumped and half absorptive and showed that one could indeed compensate the loss. More efficient way of obtaining the $\varepsilon $'$<$0 is to use metals, and we show that a combination of silver rods, supplying the negative $\varepsilon $ and pumped QDs, providing the gain necessary to compensate the loss in the silver rods [1]. \\[3pt] [1] A. Bratkovsky, E. Ponizovskaya, S-Y. Wang, P. Holmstr\"{o}m, L. Thyl\'{e}n, Y. Fu, and H. {\AA}gren, Appl. Phys. Lett. \textbf{93}, 193106 (2008) [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2025 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700