Electromagnetic scattering of high-permittivity particles on a substrate

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Enhancing the spontaneous and stimulated emission rates of magnetic quantum emitters through the Purcell effect is essential for designing high-performance quantum devices based on high quality factor and small mode volume. At room temperature, structures constructed using high-index dielectric materials have been favored due to their ability to effectively confine electromagnetic fields. However, these dielectric resonators are plagued by an inherent sensitivity to thermal variations, which are unavoidable

In this work, we design and experimentally demonstrate in the microwave range a robust metamaterial waveguide, which is formed at the boundary between two locally resonant chiral metamaterials with opposite chirality. We show that the interface states at such boundary are inherently robust to disorder in both the position and resonance frequency of subwavelength resonators. Moreover, we quantitatively demonstrate the superiority of the proposed subwavelength waveguiding over previously proposed designs, inc

The control of emission from localized light sources is an objective of outstanding relevance in nanophotonics. In a recent past, a large number of metallic nanostructures has been proposed to this end, wherein plasmonic modes are exploited as energy carriers on a subwavelength scale. As an interesting alternative, we present here the use of surface modes on patterned dielectric multilayers to deliver electromagnetic power from free-space to localized volumes and vice versa. Thanks to this low-loss energy t

It was noticed long time ago that the dielectric permittivity of BaTiO3 single crystals in the rhombohedral phase varies from observation to observation, but the microstructure mechanism behind this phenomenon remained unclear. We show that the variations in susceptibility can be related to the variable domain structure introduced by different pre-treatments at higher temperatures: Electrical depoling at room temperature leads to nano-sized domains and ultrahigh susceptibility in rhombohedral phase, whereas

We present the characterization of short-range ordered hexagonal arrays of subwavelength holes in thin gold films. The hole arrays are fabricated by a low-cost technique using convectively self-assembled polystyrene beads as an initial pattern template. Our results suggest that corrugated, short-range ordered hole arrays allow the excitation of resonant surface plasmons. This opens the door to inexpensive, large- scale and high throughput fabrication of nanophotonic devices.

We investigate the dielectric permittivity of SiO2 on Si(100) substrates using a first-principles approach. It is shown that both the static and high-frequency dielectric constants of the oxide overlayer increase when the oxide thickness is reduced. This behavior of the overlayer is found to be well reproduced by a classical two-layer model in which the pure oxide and the suboxide layer are treated as distinct dielectrics. Implications for interfaces between silicon and high-k gate oxides are discussed. (C)

In ferroelectric materials, domain wall displacement plays a key role in the dielectric properties measured with respect to the driving field amplitude and frequency. The low to medium field dielectric response in many ferroic systems can be often described by classical Rayleigh model, which is rate-independent i.e., it depends only on the strength of ac signal. However experiments show that the nonlinear parameters are frequency dependent. Thus a more general approach, which can describe both purely nonlin

We introduce a density-functional perturbational scheme based on ultrasoft pseudopotentials for calculating dielectric tensors of periodic systems. We obtain a variational functional for the second-order derivative of the energy with respect to an electric field. Our scheme makes use of the correspondence between all-electron and pseudo-wave-functions introduced in the projector augmented wave method. While we here specifically focus on ultrasoft pseudopotentials, our scheme also covers the case of norm-con

Parallel optical coherence tomography in scattering samples is demonstrated using a 58 x 58 smart-pixel detector array. A femtosecond mode-locked Ti:Sapphire laser in combination with a free space Michelson interferometer was employed to achieve 4 mum longitudinal resolution and 9 mum transverse resolution on a 260 x 260 mum field of view. We imaged a resolution target covered by an intralipid solution with different scattering coefficients as well as onion cells. (C) 2002 Published by Elsevier Science B.V.

The printing of lead zirconate titanate (PZT, Pb(Zr,Ti)O-3) piezoelectric thick films on silicon substrates is being studied for potential use as microactuators, microsensors, and micro.. transducers. A fundamental challenge in the fabrication of useful PZT thick-film devices on silicon is to sinter the PZT to high density at sufficiently low temperature to avoid mechanical or chemical degradation of the silicon substrate. The goal of the present study is to develop and implement suitable electrodes and PZT

A study of the complex permittivity in bismuth titanate was conducted to reveal the nature of an anomaly in the real part of the permittivity, which occurs below the Curie temperature. This anomaly is frequency dependent and is caused by a combination of two relaxation phenomena that appear in the imaginary part of the permittivity. One of the relaxations showed classic characteristics of an ion-jump process. Niobium doping suppressed this relaxation and eliminated the nonferroelectric anomaly in permittivi

The non-linear dielectric properties of single crystals of PbMg1/3Nb2/3O3 relaxer ferroelectric were investigated experimentally by using measurements of the dielectric permittivity of this material as a function of the DC bias and the AC driving fields. The results were analyzed using four models of the dielectric response of relaxors currently discussed in the literature, It was shown that among them only one model was consistent with the experimental data. This provides strong evidence that the mechanism

Electron energy loss spectroscopy in a high-resolution transmission electron microscope has recently been used with success to characterize the electronic properties of closed cage nanometer-size graphitic particles. In the plasmon region, the experimental data reveal interesting size-dependent variations, which are not yet fully understood. The difficulties encountered in the interpretation of the spectra are principally due to the lack of a complete theoretical treatment of the anisotropic dielectric resp

The exciton-polariton states of quantum wells embedded in planar semiconductor microcavities are usually described by assuming in-plane wave vector conservation. In this work we consider the two main k(parallel to)-scattering mechanisms, namely the polariton-phonon scattering and the in-plane structural disorder of the quantum well. We calculate the homogeneous and inhomogeneous broadening of the polariton levels and show that a detailed model of the scattering processes is essential for a theoretical deriv

Recently, local probes used in optical experiments added a new dimension to the study of the optical properties of small particles lying on a surface. Until now, several theoretical frameworks, developed to understand the interaction of optical fields with mesoscopic and nanoscopic objects, emphasized mainly the prediction of the electric near-field distributions generated by these structures. This paper demonstrates how such subwavelength dielectric surface structures also produce a particular confinement

This device for measuring Brillouin scattering includes a single laser source (11), a modulator (12) placed on the path of the light emitted by the source (11) and designed to generate a pumping signal and a test signal which are injected to one end (13) of the fibre (10), a mirror (15) arranged at the other end (14) of the fibre in order to reflect the said signals, and an electronic unit (16) for producing time encoding of these signals in order to offset them in time relative to one another so that they

Electromagnetic scattering of high-permittivity particles on a substrate

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All-metallic magnetic Purcell enhancement in a thermally stable room-temperature maser

Subwavelength robust waveguiding with chiral metamaterial waveguides

Focusing and Extraction of Light mediated by Bloch Surface Waves

Unusual dielectric behavior and domain structure in rhombohedral phase of BaTiO3 single crystals

Optical transmission properties of corrugated nanoscale hole arrays in thin gold films

Dielectric effect of a thin SiO2 interlayer at the interface between silicon and high-k oxides

Analysis of the non linear domain wall response in ferroelectric thin films

Density-functional perturbational theory for dielectric tensors in the ultrasoft pseudopotential scheme

Parallel optical coherence tomography in scattering samples using a two-dimensional smart-pixel detector array

Processing and properties of screen-printed lead zirconate titanate piezoelectric thick films on electroded silicon

Niobium doping and dielectric anomalies in bismuth titanate

Mechanism of polarization response and dielectric non-linearity of PbMg1/3Nb2/3O3 relaxor ferroelectric

Plasmon excitations in graphitic carbon spheres

Microcavity polaritons: Homogeneous and inhomogeneous broadening in the strong coupling regime

Optical magnetic near-field intensities around nanometer-scale surface structures

Method for measuring the Brillouin scattering in an optical fibre and device for implementing this method