Now showing items 41-60 of 194

  • Developing optical efficiency through optimized coating structure: biomimetic inspiration from white beetles 

    Hallam, B. T.; Hiorns, Anthony G.; Vukusic, Peter (Optical Society of America, 2009)
    The recent discovery of brilliant whiteness in ultrathin beetle scales indicated the availability of significant whiteness, brightness, and opacity from limited sample thickness. This is achieved in the beetle through ...
  • Differential ellipsometric surface plasmon resonance sensors with liquid crystal polarization modulators 

    Hooper, Ian R.; Sambles, J. Roy (American Institute of Physics, 2004)
    Differential ellipsometric interrogation of surface plasmon (SP) resonances is a technique that gives ultrahigh sensitivity to refractive index changes, and it may provide the basis for chemical and biological sensors. In ...
  • Direct Observation of Electron-to-Hole Energy Transfer in CdSe Quantum Dots 

    Hendry, Euan; Koeberg, Mattijs; Wang, F.; Zhang, H.; de Mello Donegá, C.; Vanmaekelbergh, D.; Bonn, Mischa (American Physical Society, 2006)
    We independently determine the subpicosecond cooling rates for holes and electrons in CdSe quantum dots. Time-resolved luminescence and terahertz spectroscopy reveal that the rate of hole cooling, following photoexcitation ...
  • 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 ...
  • DMAC Fatigued Shackle 

    Vickers, Andrew; Gordelier, Tessa (University of Exeter, 2013-06-04)
    Results, photos and video footage of shackle tests at DMaC. Shackle trials conducted to determine shackle behaviour of a 2.5t rated shackle for research into mooring line reliability. Break tests and fatigue tests ...
  • 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 ...
  • Efficiency of Exciton and Charge Carrier Photogeneration in a Semiconducting Polymer 

    Hendry, Euan; Schins, Juleon M.; Candeias, L. P.; Siebbeles, L. D. A.; Bonn, Mischa (American Physical Society, 2004)
    We determine the efficiencies for the formation of excitons and charge carriers following ultrafast photoexcitation of a semiconducting polymer (MEH-PPV). The simultaneous, quantitative determination of exciton and charge ...
  • Efficiency of radiative emission from thin films of a light-emitting conjugated polymer 

    Wasey, J. A. E.; Safanov, A.; Samuel, I. D. W.; Barnes, William L. (American Physical Society, 2001)
    We examine the efficiency of radiative emission from thin layers of light-emitting conjugated polymers. We compare our experimental results for photoluminescence of the conjugated polymer poly(2-methoxy, 5-(2′-ethyl-hexyloxy) ...
  • Efficient coupling of surface plasmon polaritons to radiation using a bi-grating 

    Worthing, P. T.; Barnes, William L. (American Institute of Physics, 2001)
    A nanostructured surface in the form of a bi-grating is shown to efficiently couple surface plasmon polaritons to free-space radiation in the visible part of the spectrum. Coupling was achieved for all propagation directions ...
  • 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 ...
  • Electron transport in TiO2 probed by THz time-domain spectroscopy 

    Hendry, Euan; Wang, F.; Shan, Jie; Heinz, Tony F.; Bonn, Mischa (American Physical Society, 2004)
    Electron transport in crystalline TiO2 (rutile phase) is investigated by frequency-dependent conductivity measurements using THz time-domain spectroscopy. Transport is limited by electron-phonon coupling, resulting in a ...
  • Emission of light through thin silver films via near-field coupling to surface plasmon polaritons 

    Winter, G.; Barnes, William L. (American Institute of Physics, 2006)
    We show that the emission of light from a dye layer through an adjacent thin silver film is maximal for a silver thickness of approximately 50 nm. This effect is explained as the result of competition between enhancement ...
  • 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 ...
  • Exciton and electron-hole plasma formation dynamics in ZnO 

    Hendry, Euan; Koeberg, Mattijs; Bonn, Mischa (American Physical Society, 2007)
    We employ optical pump-THz probe measurements to study the formation of excitons and electron-hole plasmas following photogeneration of a hot electron-hole gas in the direct gap semiconductor zinc oxide. Below the Mott ...
  • Experimental method for reliably establishing the refractive index of buprestid beetle exocuticle 

    Noyes, Joseph Alexander; Vukusic, Peter; Hooper, Ian R. (Optical Society of America, 2007)
    In this study we apply an existing optical characterisation technique to establish reliably the complex refractive indices of layers comprising a natural multilayer reflector in the beetle Chrysochroa raja. Its reflector ...
  • 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 ...