Search results for "Surface wave"

Surface-acoustic-wave-induced space-charge waves in electron–hole systems

2005

Abstract Space-charge waves in an electron–hole system are studied, which are excited by a moving grating provided by a surface acoustic wave (SAW). The SAW induces a constant current that may change its sign, when a constant electric field is applied opposite to the wave propagation direction. Current resonances are predicted to appear, when the SAW wavelength and frequency match the ones of the space-charge wave.

Pumping of single electrons with a traveling wave

1995

Abstract We describe the operation and performance of a one-dimensional chain of small metallic islands whose potentials are modulated in a wave-like manner. The sinusoidal voltages, applied to the gate electrodes, carry individual charges coherently through the array. In practice, the wave-like potential is induced on the gates by a surface acoustic wave (SAW) traveling on a piezoelectric substrate. The resulting transfer of charges should produce a DC current I = ± ef through the chain, where f is the frequency of the wave and the sign ofthe current depends on the value of the common DC bias of the islands as well as on the direction of the wave propagation. We observe, however, a much sm…

Surface-Wave Coupling to Single Phononic Subwavelength Resonators

2017

International audience; We propose to achieve manipulation of mechanical vibrations at the micron scale by exploiting the interaction of individual, isolated mechanical resonators with surface acoustic waves. We experimentally investigate a sample consisting of cylindrical pillars individually grown by focused-ion-beam-induced deposition on a piezoelectric substrate, exhibiting different geometrical parameters and excited by a long-wavelength surface elastic wave. The mechanical displacement is strongly confined in the resonators, as shown by field maps obtained by laser scanning interferometry. A tenfold displacement field enhancement compared to the vibration at the surface is obtained, r…

Surface waves in solar granulation observed with {\sc Sunrise}

2010

Solar oscillations are expected to be excited by turbulent flows in the intergranular lanes near the solar surface. Time series recorded by the IMaX instrument aboard the {\sc Sunrise} observatory reveal solar oscillations at high resolution, which allow studying the properties of oscillations with short wavelengths. We analyze two times series with synchronous recordings of Doppler velocity and continuum intensity images with durations of 32\thinspace min and 23\thinspace min, resp., recorded close to the disk center of the Sun to study the propagation and excitation of solar acoustic oscillations. In the Doppler velocity data, both the standing acoustic waves and the short-lived, high-deg…

Analysis of whispering gallery modes resonators: wave propagation and energy balance models

2021

Electromagnetic whispering gallery modes (WGM) are surface waves guided by the curvature of an interface. Microspheres, microdisks and microcylinders –as for example standard optical fibers– are high quality microresonators for the WGM. In fact, they can be regarded as compact and small ring resonators. Here, we present a comparison between wave propagation and energy balance models, stablishing the equivalence and discussing the basic characteristics of these two complementary approaches.

Surface Reconstruction of Transparent Objects by Polarization Imaging

2008

This paper focuses a method to acquire the surface of transparent objects for 3D measurement. The technique relies on the so called ?Shape from Polarization? technique. The principle of this polarization imaging technique is as follows: after being reflected, an unpolarized light becomes partially linearly polarized. The surface normals can be evaluated by analyzing their polarization parameters and by knowing the refractive index of the object to be controlled. Finally, the 3D shape is obtained by integrating the normals field. After an introduction to expose the problematic, section 2 exposes the principles of polarization technique. The third and the last section deal with the polarimetr…

Unguided plasmon-mode resonance in optically excited thin film: exact modal description of Kretschmann–Raether experiment

2013

With the aim of studying electromagnetic surface wave resonance, we rigorously solve the homogeneous and inhomogeneous problem associated with an optically excited thin metallic film. We then demonstrate unambiguously that the excited eigenmode engendering plasmonic resonance in the so-called Kretschmann–Raether configuration is an unguided mode (i.e., with an anti-evanescent structure). This result, challenging the classical interpretation of the outgoing wave condition applied to surface waves, permits a quantitative interpretation of the attenuated total reflection curves.

Novel prospects in hyperbolic metamaterials: Dyakonov-like surface waves

2014

Dyakonons in hyperbolic metamaterials

2013

We have analyzed surface-wave propagation that takes place at the boundary between an isotropic medium and a semi-infinite metal-dielectric periodic medium cut normally to the layers. In the range of frequencies where the periodic medium shows hyperbolic space dispersion, hybridization of surface waves (dyakonons) occurs. At low to moderate frequencies, dyakonons enable tighter confinement near the interface in comparison with pure SPPs. On the other hand, a distinct regime governs dispersion of dyakonons at higher frequencies. Full Text: PDF References Z. Ruan, M. Qiu, "Slow electromagnetic wave guided in subwavelength region along one-dimensional periodically structured metal surface", Ap…

Multi-rogue waves solutions to the focusing NLS equation and the KP-I equation

2011

Abstract. We construct a multi-parametric family of quasi-rational solutions to the focusing NLS equation, presenting a profile of multiple rogue waves. These solutions have also been used by us to construct a large family of smooth, real localized rational solutions of the KP-I equation quite different from the multi-lumps solutions first constructed in Bordag et al. (1977). The physical relevance of both equations is very large. From the point of view of geosciences,the focusing NLS equation is relevant to the description of surface waves in deep water, and the KP-I equation occurs in the description of capillary gravitational waves on a liquid surface, but also when one considers magneto…