[{"type":"speech","title":"From curved space to optical cloaking","issued":{"date-parts":[["2009"]]},"author":[{"family":"Ergin","given":"T."},{"family":"Stenger","given":"N."},{"family":"M\u00fcller","given":"J."},{"family":"Halimeh","given":"J."},{"family":"Wegener","given":"M."}],"note":"Fr\u00fchjahrstagung DPG, Fachverband Oberfl\u00e4chenphysik, Dresden, 22.-27.M\u00e4rz 2009 Verhandlungen der Deutschen Physikalischen Gesellschaft, R.6, B.44(2009) O 31.4","abstract":"Surface Science Division (O)\nWednesday\nlaritons (SPP) in metal layers with localized surface plasmon states\n(LSP) in the roughened electrode. We \ufb01nd a dielectric gap between\nelectrode and metal layers to be crucial to produce a signi\ufb01cant \ufb01eld\nenhancement.\nO 31.4\nWed 11:15\nSCH A216\nFrom curved space to optical cloaking \u2014 \u2022Tolga Ergin1 , Nicolas Stenger1 , Jonathan Mueller1 , Jad Halimeh1 , and Martin\nWegener1,2 \u2014 1 Institut f\u00a8r Angewandte Physik, Universit\u00a8t Karlu\nsruhe, 76131 Karlsruhe, Germany \u2014 2 Institut f\u00a8r Nanotechnologie,\nTransformation optics is a powerful approach to manipulate the propagation of electromagnetic waves [1]. Here, the curvature of space is\nmimicked by an anisotropic metamaterial, which is described by e\ufb00ective medium theory [2,3]. An interesting application of such composite metal-dielectric metamaterials is a non-resonant optical cloak. We\npresent full-wave \ufb01nite element simulations of feasible cloak designs\nin homogeneous medium approximation as well as in full geometry.\nReal world losses as well as microscopic phenomena are discussed and\npossible ways for the realization of such cloaking structures are shown.\n[1] U. Leonhardt, Science 312, 1777 (2006)\n[2] J.B. Pendry, et al., Science 312, 1780 (2006)\n[3] W. Cai, et al., Nature Photonics 1, 224 (2007)\nO 31.5\nWed 11:30\nSCH A216\nPoisson\u2019s Spot and Focusing of Surface Plasmon Polaritons\n\u2014 \u2022Dominic Zerulla, Brian Ashall, and Brian Vohnsen \u2014 University College Dublin, School of Physics, Dublin 4, Ireland.\nSurface plasmon polaritons (SPPs) are surface waves bound to the interface between a metal and a dielectric. Their wave characteristics\nmake them ideal candidates for the study of 2d-wave propagation on\nthe nanoscale. This was recently demonstrated in a study of Young\u2019s\nclassical interference experiment realized with SPPs. Here we examine another classic of wave optics, namely Poisson\u2019s bright spot that\nappears in the shadow region behind an obstacle. Constructive interference produced by SPPs from opposing sides of a linear obstacle\nis expected to be less apparent than in the optical case where the\n\ufb01eld across the entire rim of a circular obstacle contributes. The \ufb01nite\npropagation length of the SPPs limits the total propagation length and\nthe outcome will therefore be an elongated spot in the shadow region.\nThis can be considered as a \ufb01rst step towards realizing Fresnel lenses\nfor SPPs. Focusing is required to fully explore the potential of SPPs\nin integrated optical components and sensors. Typically, mirror-like\narrangements have been used to accomplish this. An alternative option, however, is dielectric loading to modify the phase of the SPP.\nUltimately, a high numerical aperture is required and in such a case\ntheir vectorial nature must be taken into account. Here we examine\nthe potential use of Poisson\u2019s spot for SPP con\ufb01nement and the focusing of SPPs in more general terms. Our numerical predictions are\ncompared with the outcome of preliminary experimental studies.\nO 31.6\nWed 11:45\nSCH A216\nCollective Surface Plasmons in Metallic Nanorod Arrays \u2014\n\u00b4\n\u2022Rene Kullock1 , William R. Hendren2 , Andreas Hille1 , Ste\u00a8\nfan Grafstrom1 , Paul R. Evans2 , Robert J. Pollard2 , Ron\nAtkinson2 , and Lukas M. Eng1 \u2014 1 Institut f\u00a8 r Angewandte Photou\nphysik, TU Dresden, 01062 Dresden, Germany \u2014 2 Centre for Nanostructured Media, IRCEP, The Queens University of Belfast, Belfast\nBT7 1NN, UK\nMetallic nanorod arrays exhibit several surface plasmon resonances: a\nshort-axis resonance that occurs always [1], and several long-axis resonances appearing for p-polarized light under speci\ufb01c incident angles\n[2]. Until today, time-consuming numerical calculations were needed to\nfully describe these properties theoretically. Here we use propagating\nsurface plasmons for an easier description.\nStarting with single nanowires exhibiting surface plasmon polaritons\n(SPPs) we show how the SPPs on nanowires arranged in parallel couple\nto form collective surface plasmons (CSPs), which have a drastically\nchanged dispersion. For nanorod arrays, such CSPs can be excited\nby illumination with p-polarized light. Since these arrays act as resonators, CSPs oscillate inside the structures and obey a standing wave\ncondition [3]. Hence, with our model a fast prediction of the optical\nproperties is possible which allows for an easy optimization of these\nstructures for speci\ufb01c purposes and applications.\n[1] R. Atkinson et al., Phys. Rev. B 73, 235402 (2006)\n[2] P. Evans et al., Adv. Func. Mater. 18, 1075 (2008)\n[3] R. Kullock et al., Opt. Express (2008) submitted\nO 31.7\nWed 12:00\nSCH A216\nThe Discontinuous Galerkin Time-Domain Method for\n\u00a8\nFestk\u00a8rperphysik, Universit\u00a8t Karlsruhe \u2014 2 Karlsruhe School of Opo\ntics & Photonics (KSOP), Universit\u00a8t Karlsruhe \u2014 3 DFG Centrum\nf\u00a8r Funktionelle Nanostrukturen (CFN), Universit\u00a8t Karlsruhe\nNumerical methods have become invaluable tools for research in the\n\ufb01eld of photonics and plasmonics. The Discontinuous Galerkin TimeDomain (DGTD) method, complemented by numerous extensions, allows us to solve Maxwell\u2019s equations on unstructured grids while maintaining an e\ufb03cient, explicit time-stepping scheme. Using adaptive\nmeshes we can accurately resolve complex geometric features without staircasing, thereby overcoming one of the key limitations of the\nwidely used Finite-Di\ufb00erence Time-Domain algorithm.\nAs an example, we apply the DGTD method in three dimensions to\nthe analysis of V-shaped silver nanostructures. In particular, we discuss local \ufb01eld enhancement e\ufb00ects, the onset of the quasi-static limit,\nand we investigate the possibility of coherent control.\nO 31.8\nWed 12:15\nSCH A216\nInvestigation of the dispersion relation of nanometer meander structures \u2014 \u2022Heinz Schweizer, Liwei Fu, Thomas Weiss,\nand Harald Giessen \u2014 Universit\u00a8t Stuttgart, 4.Phys.Inst., Pfa\ufb00ena\nwaldring 57\nOn the basis of a Fourier modal method we analyze the dispersion\nrelation of nanometer meander structures. Meander structures are of\nspecial interest for designing metamaterials with respect to e\ufb03cient\ncoupling of the magnetic \ufb01eld into the meander loop at all angles of\nincidence [1] and for designing plasmonic lasers [2]. To understand in\ndetail the behaviour of the meander structures we analyzed the dispersion relation of propagating electromagnetic \ufb01elds with respect to\nthe transversal component of the propagation vector. Varied coupling\nstrength between the long range and short range plasmonic modes are\nobserved. By tuning the local meander geometry and parameters such\nas width, depth, and metal layer thickness we are able to engineer the\nbandgap of the dispersion relation in a large range and in a simple\nway, which provides a large application potential for plasmonic lasers\n[2] and other plasmonic devices.\n[1] H. Schweizer et al., phys. stat. sol. (a) 204, 3886 (2007). [2] T.\nOkamoto et al, Phys. Rev. B77, 115425 (2008).\nO 32: Surface or interface magnetism\nTime: Wednesday 10:30\u201312:30\nO 32.1\nLocation: SCH A315\nWed 10:30\nSCH A315\nSurface Plasmon Excitation on Magnetoactive Materials \u2014\nLuca Sapienza and \u2022Dominic Zerulla \u2014 University College Dublin,\nSchool of Physics, Dublin 4, Ireland.\nThe interaction of surface plasmons - \ufb02uctuations in the electron\ndensity at the interface between media with dielectric constants of\nopposite sign - with magnetically ordered systems has attracted a\nlot of interest in the last ten years, as a result of the possibility of\nenhancing magneto-optical properties, like the Faraday and Kerr ef-\nfect. More recently, research has been focused on the merging of the\nareas of spintronics and plasmonics, developing of a new \ufb01eld, called\nspin-plasmonics.\nHere, we will present a systematic study of the excitation of surface\nplasmons on ferromagnetic materials in multilayered structures composed of thin \ufb01lms of nickel, iron, cobalt, c","kit-publication-id":"230075137"}]