Now showing items 1-15 of 15

    • Combined-field solution of composite geometries involving open and closed conducting surfaces 

      Ergül Ö.; Gürel, L. (2005)
      Combined-field integral equation (CFIE) is modified and generalized to formulate the electromagnetic problems of composite geometries involving both open and closed conducting surfaces. These problems are customarily ...
    • Coupling enhancement of split ring resonators on graphene 

      Cakmakyapan, S.; Caglayan, H.; Ozbay, E. (Pergamon Press, 2014-12)
      Metallic split ring resonator (SRR) structures are used in nanophotonics applications in order to localize and enhance incident electromagnetic field. Electrically controllable sheet carrier concentration of graphene ...
    • Efficient computation of surface fields excited on a dielectric-coated circular cylinder 

      Erturk, V. B.; Rojas, R. G. (IEEE, 2000-10)
      An efficient method to evaluate the surface fields excited on an electrically large dielectric-coated circular cylinder is presented. The efficiency of the method results from the circumferentially propagating representation ...
    • Highly doped silicon micromachined photonic crystals 

      Temelkuran, B.; Bayindir, M.; Ozbay, E.; Kavanaugh, J. P.; Sigalas, M. M.; Tuttle, G. (IEEE, Piscataway, NJ, United States, 2000)
      Summary form only given. Photonic crystals are periodic structures with the property of reflecting the electromagnetic (EM) waves in all directions within a certain frequency range. These structures can be used to control ...
    • Improving RF safety in MRI by modifying the electric field distribution 

      Eryaman, Y.; Atalar, E. (2011)
      In this work we demonstrate that the radiofrequency (RF) electric field in magnetic resonance imaging (MRI) can be modified in order to enhance patient safety. The heating of metallic devices in MRI is directly related to ...
    • Metamaterial based cloaking with sparse distribution of spiral resonators 

      Guven, K.; Saenz, E.; Gonzalo, R.; Ozbay, E.; Tretyakov, S. (2010)
      We investigate the application of a metamaterial that is formed by the sparse distribution of spiral resonators as an optical transformation medium is in order to achieve electromagnetic cloaking. The well-known Clausius-Mossotti ...
    • Microcavity lasers on polymer materials: Boundary integral equation modeling and experiments 

      Nosich, A.I.; Smotrova, E.I.; Lebental, M.; Sukharevsky I.O.; Altintas, A. (Institute of Electrical and Electronics Engineers Inc., 2015)
      We consider the modeling and experiments with polymer dye-doped lasers shaped as thin flat cavities, allowing one to consider them as two-dimensional (2-D) active cavities. We focus our modeling on the H-polarized ...
    • A modified equivalence principle for open surfaces 

      Takrimi, M.; Gurel, L. (Institute of Electrical and Electronics Engineers Inc., 2014)
      We introduce a new method for expanding equivalent surface current densities over open surfaces. The new method is based on the equivalence principle, which is theoretically used with closed surfaces. Utilizing low-order ...
    • Observation of defect formation in metamaterials 

      Caglayan H.; Bulu I.; Loncar, M.; Ozbay, E. (Optical Society of America, 2008)
      We report subwavelength localization of electromagnetic fields within cavities based on metamaterials. Cavity resonances are observed in the transmission spectrum of a split ring resonator and composite metamaterials cavity ...
    • Rigorous solutions of electromagnetic problems involving hundreds of millions of unknowns 

      Ergül, O.; Gürel, L. (IEEE, 2011)
      Accurate simulations of real-life electromagnetic problems with integral equations require the solution of dense matrix equations involving millions of unknowns. Solutions of these extremely large problems cannot be easily ...
    • A simple analytical expression for the gradient induced potential on active implants during MRI 

      Turk, E.A.; Kopanoglu, E.; Guney, S.; Bugdayci, K.E.; Ider, Y. Z.; Erturk, V. B.; Atalar, E. (2012)
      During magnetic resonance imaging, there is an interaction between the time-varying magnetic fields and the active implantable medical devices (AIMD). In this study, in order to express the nature of this interaction, ...
    • Two-dimensional complex parity-time-symmetric photonic structures 

      Turduev, M.; Botey, M.; Giden, I.; Herrero, R.; Kurt, H.; Ozbay, E.; Staliunas, K. (American Physical Society, 2015-02)
      We propose a simple realistic two-dimensional complex parity-time-symmetric photonic structure that is described by a non-Hermitian potential but possesses real-valued eigenvalues. The concept is developed from basic ...
    • Universal infrared absorption spectroscopy using uniform electromagnetic enhancement 

      Ayas S.; Bakan, G.; Ozgur E.; Celebi, K.; Dana, A. (American Chemical Society, 2016)
      Infrared absorption spectroscopy has greatly benefited from the electromagnetic field enhancement offered by plasmonic surfaces. However, because of the localized nature of plasmonic fields, such field enhancements are ...
    • Validation of electromagnetic field enhancement in near-infrared through Sierpinski fractal nanoantennas 

      Cakmakyapan, S.; Cinel, N.A.; Cakmak, A.O.; Ozbay, E. (Optical Society of American (OSA), 2014)
      We introduced fractal geometry to the conventional bowtie antennas. We experimentally and numerically showed that the resonance of the bowtie antennas goes to longer wavelengths, after each fractalization step, which is ...
    • Windowed equivalence principle for open surfaces 

      Takrimi, M.; Gürel, L. (2013)
      We introduce a modified current expansion scheme over open surfaces based on the equivalence theorem, which employs closed surfaces, in principle. Weighting the expansion coefficients with a suitable window function ...