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Now showing items 21-40 of 115

  • Direct mapping of surface plasmon dispersion using imaging scatterometry 

    Hibbins, Alastair P.; Constant, Thomas J.; Lethbridge, Alfred J.; Sambles, J. Roy; Stone, Edmund K.; Vukusic, Peter (American Institute of Physics, 2013)
    The iso-frequency contours of diffracted surface plasmons on metallic bigratings have been directly recorded using imaging scatterometry. Metallic rectangular bigratings, formed of two “crossed” surface relief gratings, ...
  • Direct Optical Quantification of Backflow in a 90° Twisted Nematic Cell 

    Smith, N. J.; Tillin, M. D.; Sambles, J. Roy (American Physical Society, 2002)
    Optical guided mode observations of the transient director profile (optical tensor distribution) during the relaxation of a 90° twisted nematic cell directly reveals backflow. In the first 6 ms of the relaxation process, ...
  • Dispersion of surface plasmon polaritons on short-pitch metal gratings 

    Hooper, Ian R.; Sambles, J. Roy (American Physical Society, 2002)
    The dispersion of surface plasmon polaritons (SPPs) has been calculated for short-pitch metal gratings for various depths. For gratings with depths greater than their pitch very flat SPP bands are formed in the zero-order ...
  • Double-period zero-order metal gratings as effective selective absorbers 

    Tan, W.-C.; Sambles, J. Roy; Preist, T. W. (American Physical Society, 2000)
    The electromagnetic response of a zero-order metal grating having a primary deep short-period component and a shallow long-period component is modeled. It is found that such a metal grating has an unusual surface-plasmon-polariton ...
  • Dynamic control of visible radiation by a liquid crystal filled Fabry-Pérot etalon 

    Jewell, Sharon A.; Cornford, Stephen Leslie; Sambles, J. Roy (American Institute of Physics, 2007)
    A liquid crystal filled Fabry-Pérot etalon has been constructed to control the resonant transmission of electromagnetic radiation over the visible range of the spectrum. This has been achieved through the use of a 1.5 µm ...
  • Dynamical process of switch-off in a supertwisted nematic cell 

    Yang, Fuzi; Dong, Youmei; Ruan, Lizhen; Sambles, J. Roy (American Institute of Physics, 2004)
    The switch-off dynamics of a 180° supertwisted nematic (STN) are explored in detail by using a convergent beam system and the fully leaky guided-mode technique. From the dynamical guided-mode data and using the Ericksen–Leslie ...
  • Electromagnetic resonances of a multilayer metal-dielectric stack 

    Gadsdon, Martyn Richard; Parsons, J.; Sambles, J. Roy (Optical Society of America, 2009)
    The electromagnetic resonances of multilayer metal–dielectric stacks are investigated. These structures support periodic bandpass regions, whose band edges may be predicted by considering the character of the fields inside ...
  • Electromagnetic response of closely spaced metal meshes 

    Taylor, Melita C.; Hibbins, Alastair P.; Sambles, J. Roy (American Physical Society, 2012)
    The electromagnetic transmittance of a double layer of identical square arrays of square holes (mesh) in a perfectly conducting sheet is analytically modeled using a modal matching technique. The structure supports families ...
  • Enhanced microwave transmission through a patterned metal film 

    Kelly, Robert J.; Lockyear, Matthew J.; Suckling, James R.; Sambles, J. Roy; Lawrence, Christopher R. (American Institute of Physics, 2007)
    Selective transmission of radiation through a two-dimensional array of subwavelength slits in an otherwise opaque thin metal film is presented at microwave frequencies. Individual slits are modified with the addition of ...
  • Excitation of remarkably nondispersive surface plasmons on a nondiffracting, dual-pitch metal grating 

    Hibbins, Alastair P.; Sambles, J. Roy; Lawrence, Christopher R. (American Institute of Physics, 2002)
    A nondiffracting metallic lamellar grating formed from three equally spaced grooves per repeat period, with one being slightly shallower than the other two is examined at microwave frequencies. When filled with a slightly ...
  • Exploration of the surface director profile in a liquid crystal cell using coupling between the surface plasmon and half-leaky optical guided modes 

    Yang, Fuzi; Ruan, Lizhen; Sambles, J. Roy (American Institute of Physics, 2008)
    The half-leaky guided mode geometry with a thin metal tunnel barrier as one cladding layer is used to explore the distribution of the director very near to the surface in a hybrid aligning nematic liquid crystal cell. From ...
  • Finite conductance governs the resonance transmission of thin metal slits at microwave frequencies 

    Suckling, James R.; Hibbins, Alastair P.; Lockyear, Matthew J.; Preist, T. W.; Sambles, J. Roy; Lawrence, Christopher R. (American Physical Society, 2004)
    Fabry-Perot–like resonant transmission of microwave radiation through a single subwavelength slit in a thick aluminum plate is quantified for a range of slit widths. Surprisingly, and in contrast to previous studies [e.g., ...
  • Flow-driven transition and associated velocity profiles in a nematic liquid-crystal cell 

    Jewell, Sharon A.; Cornford, Stephen Leslie; Yang, Fuzi; Cann, P. S.; Sambles, J. Roy (American Physical Society, 2009)
    The alignment properties and distribution of flow speed during Poiseuille flow through a microchannel of a nematic liquid crystal in a cell with homeotropic surface alignment has been measured using a combination of ...
  • Flow-Induced Twist-Compression in a Twisted Nematic Cell 

    Ruan, Lizhen; Sambles, J. Roy (American Physical Society, 2003)
    An optical convergent-beam guided-wave technique is used to explore in detail the dynamic flow effects in a twisted nematic cell. During switch-on it is found that the dynamic flow compresses the director twist to regions ...
  • Fluorescent dyes as a probe for the localized field of coupled surface plasmon-related resonances 

    Kreiter, M.; Neumann, T.; Mittler, S.; Knoll, W.; Sambles, J. Roy (American Physical Society, 2001)
    The fluorescence light of Cy5 dye molecules in the vicinity of a metal grating is studied for varying directions of both the exciting and the emitted light. A different angular dependence of the intensity of the emitted ...
  • Grating-coupled surface plasmons at microwave frequencies 

    Hibbins, Alastair P.; Sambles, J. Roy; Lawrence, Christopher R. (American Institute of Physics, 1999)
    This work presents a detailed investigation of electromagnetic coupling to the surface plasmon-polariton (SPP) at microwave frequencies. We have recorded the wavelength-dependent reflectivity from a metallic sinusoidal ...
  • Gratingless enhanced microwave transmission through a subwavelength aperture in a thick metal plate 

    Hibbins, Alastair P.; Sambles, J. Roy; Lawrence, Christopher R. (American Institute of Physics, 2002)
    Remarkably enhanced transmission of microwave radiation through a single subwavelength slit in a thick metallic substrate surrounded by just a pair of parallel deep and narrow grooves is recorded. By also patterning the ...
  • Grazing-incidence iridescence from a butterfly wing 

    Lawrence, Christopher R.; Vukusic, Peter; Sambles, J. Roy (Optical Society of America, 2002)
    The Troides magellanus butterfly exhibits a specialized iridescence that is visible only when its hind wings are both illuminated and viewed at near-grazing incidence. The effect is due to the presence of a constrained ...
  • Heavily loaded ferrite-polymer composites to produce high refractive index materials at centimetre wavelengths 

    Parke, L.; Hooper, Ian R.; Hicken, R.J.; Dancer, C.E.J.; Grant, P.S.; Youngs, I.J.; Sambles, J. Roy; Hibbins, Alastair P. (American Institute of Physics (AIP), 2013)
    A cold-pressing technique has been developed for fabricating composites composed of a polytetrafluoroethylene-polymer matrix and a wide range of volume-fractions of MnZn-ferrite filler (0%–80%). The electromagnetic properties ...
  • Importance of diffraction in determining the dispersion of designer surface plasmons 

    Hendry, Euan; Hibbins, Alastair P.; Sambles, J. Roy (American Physical Society, 2008)
    By employing a modified modal matching approach, we obtain explicit analytical expressions relating frequency to in-plane wave vector for the surface electromagnetic mode confined at the interface between vacuum and a ...