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Near and far field

About: Near and far field is a research topic. Over the lifetime, 15922 publications have been published within this topic receiving 220571 citations.


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Journal ArticleDOI
TL;DR: To the authors' knowledge, this is the first time that both far- and near-field spectroscopy are carried out for identical individual nanostructures interacting via a subnanometer gap.
Abstract: Strongly coupled plasmons in a system of individual gold nanoparticles placed at subnanometer distance to a gold film (nanoparticle-on-plane, NPOP) are investigated using two complementary single particle spectroscopy techniques. Optical scattering spectroscopy exclusively detects plasmon modes that couple to the far field via their dipole moment (bright modes). By using photoemission electron microscopy (PEEM), we detect in the identical NPOPs near-field modes that do not couple to the scattered far field (dark modes) and are characterized by a strongly enhanced nonlinear electron emission process. To our knowledge, this is the first time that both far- and near-field spectroscopy are carried out for identical individual nanostructures interacting via a subnanometer gap. Strongly resonant electron emission occurs at excitation wavelengths far off-resonant in the scattering spectra.

80 citations

Journal ArticleDOI
TL;DR: In this article, a complete antenna pattern characterization procedure for spherical near-field antenna measurements employing a high-order probe and a full probe correction is described, which allows an arbitrary antenna to be used as a probe.
Abstract: A complete antenna pattern characterization procedure for spherical near-field antenna measurements employing a high-order probe and a full probe correction is described. The procedure allows an (almost) arbitrary antenna to be used as a probe. Different measurement steps of the procedure and the associated data processing are described in detail, and comparison to the existing procedure employing a first-order probe is made. The procedure is validated through measurements.

80 citations

Journal ArticleDOI
TL;DR: In this article, the performance of the ridge waveguide as a near-field aperture in data storage systems is investigated using finite element method (FEM) and finite difference time-domain (FDTD) based software.
Abstract: The performance of the ridge waveguide as a near-field aperture in data storage systems is investigated. Finite element method (FEM) and finite-difference time-domain (FDTD) based software are used in the numerical simulations. To verify their accuracy at optical frequencies, the FEM and FDTD are first compared to analytical results. The accuracy of these techniques for modeling ridge waveguides at optical frequencies is also evaluated by comparing their results with each other for a plane wave illumination. The FEM, which is capable of modeling focused beams, is then used to simulate various geometries involving ridge waveguides. Near-field radiation from ridge waveguide transducer is expressed in terms of power density quantities. Previous studies in the literature consider the performance of the transducer in free space, rather than in the presence of a recording magnetic medium. The effect of the recording magnetic medium on the transmission efficiency and spot size is discussed using numerical simula...

80 citations

Journal ArticleDOI
TL;DR: In this paper, the authors explored the non-thermal and anisotropic nature of the ablation process in femtosecond laser pulses by temporally resolved scattering methods and by post-mortem analysis.
Abstract: The high field strength of femtosecond laser pulses leads to nonlinear effects during the interaction with condensed matter. One such effect is the ablation process, which can be initiated below the threshold of common thermal ablation if the excitation pulses are sufficiently short. This effect leads to structure formation, which is anisotropic because of the polarization properties of the near field and can result in pattern sizes below the resolution limit of light. These effects are explored by temporally resolved scattering methods and by post-mortem analysis to show the non-thermal and anisotropic nature of this process. The near-field distribution of plasmon modes can be tailored to a large extent in order to obtain control of the pattern formation.

80 citations

Journal ArticleDOI
TL;DR: In this paper, the optical forces due to the radiation of a thermal source were studied using the Lifshitz model and two contributions were found: a repulsive "wind" component and a dispersive "surface wave" component.
Abstract: We study the optical forces due to the radiation of a thermal source. Our model consists of a particle modelled by a dipole above a half-space at temperature T. The fluctuating fields are computed using the Lifshitz model. We find two contributions to the force: a repulsive 'wind' component and a dispersive force mainly due to the contribution of thermally excited surface waves. It is found that for SiC material, the latter is repulsive in the very near field. The usual van der Waals force is larger by a factor of approximately ten for submicron size particles.

80 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023132
2022281
2021376
2020460
2019640
2018604