7,879 research outputs found

    Corrosion Behavior of Parylene-Metal-Parylene Thin Films in Saline

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    In this paper, we study the corrosion behavior of parylene-metal-parylene thin films using accelerated-lifetime soak tests. The samples under test are thin film resistors with a 200 nm layer of Au sandwiched by parylene-C on both sides, fabricated with parylene-metal skin technology. The samples are tested in hot saline both passively and actively, and different failure modes are observed using optical and electron-beam metrologies. Bubbles and delamination are first seen in the samples after 2 days of soaking under passive conditions, and followed by metal corrosion. While under active conditions, either bubbles or parylene breakdowns are observed depending on the thickness of parylene packaging. These results contribute to a better understanding of the failure mechanisms of parylene packaging in body fluids

    Electrodynamics of moving media First semiannual report, 1 May - 1 Nov. 1965

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    Electrodynamics of moving media - Minkowski covariant formulation - Radiation due to oscillating dipole in vacuum - Field of moving charge in bounded region and Cerenkov radiatio

    Verification of a localization criterion for several disordered media

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    We analytically compute a localization criterion in double scattering approximation for a set of dielectric spheres or perfectly conducting disks uniformly distributed in a spatial volume which can be either spherical or layered. For every disordered medium, we numerically investigate a localization criterion, and examine the influence of the system parameters on the wavelength localization domains.Comment: 30 pages, LateX, amstex, revtex styles, 20 figure

    Fermat's principle of least time in the presence of uniformly moving boundaries and media

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    The refraction of a light ray by a homogeneous, isotropic and non-dispersive transparent material half-space in uniform rectilinear motion is investigated theoretically. The approach is an amalgamation of the original Fermat's principle and the fact that an isotropic optical medium at rest becomes optically anisotropic in a frame where the medium is moving at a constant velocity. Two cases of motion are considered: a) the material half-space is moving parallel to the interface; b) the material half-space is moving perpendicular to the interface. In each case, a detailed analysis of the obtained refraction formula is provided, and in the latter case, an intriguing backward refraction of light is noticed and thoroughly discussed. The results confirm the validity of Fermat's principle when the optical media and the boundaries between them are moving at relativistic speeds.Comment: 11 pages, 6 figures, RevTeX 4, comments welcome; V2: revised, Fig. 7 added; V3: several typos corrected, accepted for publication in European Journal of Physics (online at: http://stacks.iop.org/EJP/28/933

    Determination of the forward slope in p pp~p and pˉ p\bar p~p elastic scattering up to LHC energy

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    In the analysis of experimental data on ppp p (or pˉp\bar p p) elastic differential cross section it is customary to define an average forward slope bb in the form exp(bt)\exp{(-b|t|)}, where tt is the momentum transfer. Taking as working example the results of experiments at Tevatron and SPS, we will show with the help of the impact picture approach, that this simplifying assumption hides interesting information on the complex non-flip scattering amplitude, and that the slope bb is not a constant. We investigate the variation of this slope parameter, including a model-independent way to extract this information from an accurate measurement of the elastic differential cross section. An extension of our results to the LHC energy domain is presented in view of future experiments.Comment: 12 pages, 6 figures, to appear in EPJ

    The Off-Shell Electromagnetic T-matrix: momentum-dependent scattering from spherical inclusions with both dielectric and magnetic contrast

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    The momentum- and frequency-dependent T-matrix operator for the scattering of electromagnetic waves by a dielectric/conducting and para- or diamagnetic sphere is derived as a Mie-type series, and presented in a compact form emphasizing various symmetry properties, notably the unitarity identity. This result extends to magnetic properties one previously obtained for purely dielectric contrasts by other authors. Several situations useful to spatially-dispersive effective-medium approximations to one-body order are examined. Partial summation of the Mie series is achieved in the case of elastic scattering.Comment: 22 pages. Preprint of a paper to appear in `Waves in Complex And Random Media' ((c) Taylor and Francis, 2011

    Weak and Strong coupling regimes in plasmonic-QED

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    We present a quantum theory for the interaction of a two level emitter with surface plasmon polaritons confined in single-mode waveguide resonators. Based on the Green's function approach, we develop the conditions for the weak and strong coupling regimes by taking into account the sources of dissipation and decoherence: radiative and non-radiative decays, internal loss processes in the emitter, as well as propagation and leakage losses of the plasmons in the resonator. The theory is supported by numerical calculations for several quantum emitters, GaAs and CdSe quantum dots and NV centers together with different types of resonators constructed of hybrid, cylindrical or wedge waveguides. We further study the role of temperature and resonator length. Assuming realistic leakage rates, we find the existence of an optimal length at which strong coupling is possible. Our calculations show that the strong coupling regime in plasmonic resonators is accessible within current technology when working at very low temperatures (<4K). In the weak coupling regime our theory accounts for recent experimental results. By further optimization we find highly enhanced spontaneous emission with Purcell factors over 1000 at room temperature for NV-centers. We finally discuss more applications for quantum nonlinear optics and plasmon-plasmon interactions.Comment: published as Phys. Rev. B 87, 115419 (2013
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