Now showing items 155-174 of 865

  • Determination of limits on disc masses around six pulsars at 15 and 90 mum 

    Koch-Miramond, L; Haas, M; Pantin, E; Podsiadlowski, P; Naylor, Tim; Sauvage, M (EDP Sciences, 2002-05-01)
    We have searched for evidence of emission at 15 mum with ISOCAM and at 90 mum with ISOPHOT from dust orbiting six nearby pulsars, both in binaries and in isolation, located at distances between about 100 to 1000 pc. No ...
  • Determination of the director profile in a nematic cell from guided wave data: an inverse problem 

    Cornford, Stephen Leslie; Taphouse, T. S.; Newton, C. J. P.; Sambles, J. Roy (Institute of Physics and Deutsche Physikalische Gesellschaft, 2007)
    We consider an inverse problem: the estimation of the nematic director profile from experimental fully leaky guided mode data. This inverse problem is ill-posed in that small changes in the data may lead to large changes ...
  • Determination of the Thickness of Al2O3 Barriers in Magnetic Tunnel Junctions 

    Buchanan, J.D.R.; Hase, T.P.A.; Tanner, B.K.; Hughes, N.D.; Hicken, R.J. (American Institute of Physics, 2002)
    The barrier thickness in magnetic spin-dependent tunnel junctions with Al2O3 barriers has been measured using grazing incidence x-ray reflectivity and by fitting the tunneling current to the Simmons model. We have studied ...
  • Determining atmospheric conditions at the terminator of the hot Jupiter HD 209458b 

    Sing, David K.; Vidal-Madjar, A.; Lecavelier des Etangs, A.; Desert, J.-M.; Ballester, G.; Ehrenreich, D. (IOP Publishing for American Astronomical Society, 2008)
    We present a theoretical model fit to the HST STIS optical transit transmission spectrum of HD 209458b. In our fit, we use the sodium absorption line profile along with the Rayleigh scattering by H2 to help determine the ...
  • Determining the terahertz optical properties of subwavelength films using semiconductor surface plasmons 

    Isaac, Thomas Henry; Barnes, William L.; Hendry, Euan (American Institute of Physics, 2008)
    By employing a combination of time-domain measurements and numerical calculations, we demonstrate that the semiconductor InSb supports a strongly confined surface plasmon (SP) in the terahertz frequency range. We show that ...
  • Developing fibre optic Raman probes for applications in clinical spectroscopy 

    Stevens, O; Iping Petterson, IE; Day, JCC; Stone, N (Royal Society of Chemistry, 2016-03-09)
    Raman spectroscopy has been shown by various groups over the last two decades to have significant capability in discriminating disease states in bodily fluids, cells and tissues. Recent development in instrumentation, ...
  • 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 ...
  • Diffractive coupling in gold nanoparticle arrays and the effect of disorder 

    Auguié, Baptiste; Barnes, William L. (Optical Society of America, 2009)
    Two-dimensional arrays of gold nanoparticles with a periodicity commensurate with the wavelength of resonant excitation of localized plasmons have been shown to exhibit a strong long-range interaction between particles. ...
  • Dirac plasmons in bipartite lattices of metallic nanoparticles 

    Sturges, TJ; Woollacott, Claire; Weick, Guillaume; Mariani, Eros (IOP Publishing, 2015-02-12)
    We study theoretically "graphene-like" plasmonic metamaterials constituted by two-dimensional arrays of metallic nanoparticles, including perfect honeycomb structures with and without inversion symmetry, as well as generic ...
  • Dirac-like plasmons in honeycomb lattices of metallic nanoparticles 

    Weick, Guillaume; Woollacott, Claire; Barnes, William L.; Hess, Ortwin; Mariani, Eros (American Physical Society, 2013)
    We consider a two-dimensional honeycomb lattice of metallic nanoparticles, each supporting a localized surface plasmon, and study the quantum properties of the collective plasmons resulting from the near-field dipolar ...
  • Direct detection of pure AC spin-current by x-ray pump-probe measurements 

    J. Li; Shelford; P. Shafer; A. Tan; J. X. Deng; P. S. Keatley; C. Hwang; E. Arenholz; G. van der Laan; Hicken, RJ; Z. Q. Qiu (American Physical Society, 2016-08-11)
    Despite recent progress in spin-current research, the detection of spin current has mostly remained indirect. By synchronizing a microwave waveform with synchrotron x-ray pulses, we use the ferromagnetic resonance of the ...
  • Direct excitation of propagating spin waves by focused ultrashort optical pulses 

    Au, Y.; Dvornik, Mykola; Davison, T.; Ahmad, E.; Keatley, Paul Steven; Vansteenkiste, A.; Van Waeyenberge, B.; Kruglyak, V.V. (American Physical Society, 2013)
    An all-optical experiment long utilized to image phonons excited by ultrashort optical pulses has been applied to a magnetic sample. In addition to circular ripples due to surface acoustic waves, we observe an X-shaped ...
  • 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 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 observation of magnetization dynamics generated by nano-contact spin-torque vortex oscillators 

    Keatley, PS; Sani, SR; Hrkac, G; Mohseni, SM; Dürrenfeld, P; Loughran, THJ; Åkerman, J; Hicken, RJ (American Physical Society, 2016)
    Time-resolved scanning Kerr microscopy has been used to directly image the magnetization dynamics of nano-contact (NC) spin-torque vortex oscillators (STVOs) when phase-locked to an injected microwave (RF) current. The ...
  • Direct observation of negative-index microwave surface waves. 

    Dockrey, JA; Horsley, SA; Hooper, Ian R.; Sambles, JR; Hibbins, Alastair P. (Nature Publishing Group: Open Access Journals - Option C, 2016-02-23)
    Waves propagating in a negative-index material have wave-front propagation (wavevector, k) opposite in direction to that of energy flow (Poynting vector, S). Here we present an experimental realisation at microwave frequencies ...
  • 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, ...
  • Direct spectrum of the benchmark t dwarf HD 19467 B 

    Crepp, JR; Rice, EL; Veicht, A; Aguilar, J; Pueyo, L; Giorla, P; Nilsson, R; Luszcz-Cook, SH; Oppenheimer, R; Hinkley, S; Brenner, D; Vasisht, G; Cady, E; Beichman, CA; Hillenbrand, LA; Lockhart, T; Matthews, CT; Roberts, LC; Sivaramakrishnan, A; Soummer, R; Zhai, C (American Astronomical Society / IOP Publishing, 2015-01-06)
    HD 19467 B is presently the only directly imaged T dwarf companion known to induce a measurable Doppler acceleration around a solar-type star. We present spectroscopy measurements of this important benchmark object taken ...
  • Directly observing continuum emission from self-gravitating spiral waves 

    Hall, C; Forgan, D; Rice, K; Harries, TJ; Klaassen, PD; Biller, B (Oxford University Press (OUP) / Royal Astronomical Society, 2016)
    We use a simple, self-consistent, self-gravitating semi-analytic disc model to conduct an examination of the parameter space in which self-gravitating discs may exist. We then use Monte-Carlo radiative transfer to generate ...