Francisco José González González

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Light scattering by an array of alternating electric and magnetic nanoparticles is analyzed in detailed. Specific geometrical conditions are derived, where such an array behaves like double-negative particles, leading to a suppression of the backscattered intensity. This effect is very robust and could be used to produce double-negative metamaterials using(More)
Numerical analyses of the ultraviolet and visible plasmonic spectra measured from hemispherical gallium nanostructures on dielectric substrates reveal that resonance frequencies are quite sensitive to illumination angle and polarization in a way that depends on nanostructure size, shape, and substrate. Large, polarization-dependent splittings arise from the(More)
PURPOSE By means of an individualized optical model of the visual system, a customized surgical correction is proposed to achieve emmetropia and best visual acuity. METHODS The study included 64 eyes with myopia or myopic astigmatism that underwent LASIK with the Nidek EC-5000 excimer laser. The mean age was 33 years (19 to 54 yr). Mean myopia was -3.70 D(More)
the intensity statistics of the s-polarized electromagnetic field scattered from randomly rough, perfectly conducting, one-dimensional surfaces are studied in the case of surface transverse correlation lengths larger than the wavelength. In particular, the speckle contrast, the intensity probability-density function, and the mean scattered intensity are(More)
The ultraviolet (UV) range presents new challenges for plasmonics, with interesting applications ranging from engineering to biology. In previous research, gallium, aluminum, and magnesium were found to be very promising UV plasmonic metals. However, a native oxide shell surrounds nanostructures of these metals that affects their plasmonic response. Here,(More)
The spectral evolution of the degree of linear polarization (PL) at a scattering angle of 90° is studied numerically for high refractive index (HRI) dielectric spherical nanoparticles. The behaviour of PL(90°) is analysed as a function of the refractive index of the surrounding medium and the particle radius, and it is compared with the more conventional(More)
The presence of local inhomogeneities in corneal tissue after refractive surgery has an influence on visual performance. Here we focus on the corneal ablation associated with Lasik surgery and its effect on the modulation transfer function (MTF) that we obtained by modifying a personalized Kooijman model. Inhomogeneities induced by the ablation occur in the(More)
The near-field electromagnetic scattering intensity resonances are redshifted in frequency with respect to their far-field counterparts. We derive simple, approximate, analytical formulas for this shift in the case of a plane wave interacting with a dielectric sphere. Numerical results comparing the approximate formulas to the numerically exact solutions(More)
The influence of increasing the core size of Ag-Si core-shell nanoparticles has been investigated by using the values of the linear polarization degree at a right-angle scattering configuration, [Formula: see text]. Changes in dipolar resonances and scattering directionality conditions as a function of the core radius (R int) for a fixed shell size(More)
The ability to infer near-field scattering properties from far-field measurements is of paramount importance in nano-optics. Recently we derived an approximate formula for predicting the frequency shift between near- and far-field intensity peaks in the case of a dielectric sphere. In this work we demonstrate that almost an identical formula can be used to(More)