scholarly journals Mode spectra of magnetic and dielectric plasmon spheres obtained from Mie scattering and free oscillation theories

2021 ◽  
Vol 95 (1) ◽  
Author(s):  
Jerzy Krupka ◽  
Bartlomiej Salski ◽  
Adam Pacewicz ◽  
Pawel Kopyt

Abstract This paper presents Mie scattering theory as compared to rigorous electromagnetic theory of free oscillations in magnetic and electric plasmon spheres. It is shown that the maxima of Mie scattering and absorption spectra well correspond to resonance frequencies of plasmon modes occurring in dielectric and magnetic spheres, similarly as it takes place for ordinary dielectric resonator modes. Mie theory is well applicable to determine resonance frequencies and scattering parameters of spherical plasmons. However, this theory cannot be applied to determine intrinsic properties of modes induced in the object by the incident plane wave, like quality factors. On the contrary, rigorous electromagnetic theory of free oscillations allows one to determine the complex resonance frequency of each mode that can occur in a given object, and the corresponding quality factor accounting for various kind of losses, including medium and radiation losses. The advantage of the free oscillations theory, as shown in this paper, is in the determination of the quality factors of modes occurring in magnetic plasmon spheres made of a strongly dispersive magnetic medium. Graphical Abstract

2007 ◽  
Vol 48 (1) ◽  
pp. 303 ◽  
Author(s):  
M. Joseph Costello ◽  
So¨nke Johnsen ◽  
Kurt O. Gilliland ◽  
Christopher D. Freel ◽  
W. Craig Fowler

2004 ◽  
Vol 808 ◽  
Author(s):  
J. Gaspar ◽  
T. Adrega ◽  
V. Chu ◽  
J. P. Conde

ABSTRACTThis paper describes the fabrication and characterization of thin-film nanocrystalline silicon microresonators processed at temperatures below 110°C on glass substrates. The microelectromechanical structures consist of surface micromachined bridges of boron-doped hydrogenated nanocrystalline silicon (p+-nc-Si:H) deposited at 100°C by hot-wire chemical vapor deposition (HWCVD). The microbridges, which are suspended over an Al gate electrode, are electrostatically actuated and the mechanical resonance is detected in vacuum using an optical setup. The resonance frequency and energy dissipation in p+-nc-Si:H based resonators are studied as a function of the geometrical dimensions of the microstructures. Resonance frequencies between 700 kHz and 36 MHz and quality factors as high as 2000 are observed. A Young's modulus of 160 GPa for the structural bridge film is extracted from the experimental data using an electromechanical model and the main intrinsic energy dissipation mechanisms in nc-Si:H microresonators are discussed.


1976 ◽  
Vol 54 (4) ◽  
pp. 349-352
Author(s):  
A. J. Patitsas ◽  
F. Robillard ◽  
B. H. Kaye

Simple relations have been obtained, by numerical methods, between the diameter D of a spherical void (bubble) in a conducting medium of a given refractive index and the angular positions of the extrema of the Mie scattering intensities from the voids. The extrema are counted from the forward direction. These relations allow the determination of the positions of the extrema for a given diameter, or the reverse, without computational aids. The real part of the refractive index was varied from 1.25 to 15.00 and the imaginary part from 0.0 to 22.50. The size parameter α = πD/λ was varied in all cases from 4.00 to 24.00. The variable λ represents the wavelength of the incident radiation. These findings could thus be related to the scattering of microwaves by bubbles in water. Similar relations have also been obtained regarding the scattering of scalar waves by spherical voids. This corresponds to scattering of Schrödinger waves from complex spherical barrier potentials.


Author(s):  
William F. Godoy ◽  
Paul E. DesJardin

This study uses the correlated-k (c-k) and Mie scattering theory to evaluate absorption and scattering properties of participating media for fire suppression environments. In this approach the irregular spectral distribution of the radiative properties is reordered into cumulative distribution functions on a narrow band basis increasing the speed of property evaluation when compared to line-by-line calculations. The spectral properties are determined from the HITEMP database for carbon dioxide and water vapor, along with Mie and Rayleigh scattering theories for water droplets and soot particles, respectively. Results are presented for radiative heat transfer in a 1D domain for several mixtures and show that the attenuation of the radiation is highly sensitive to the water droplet size, mass loading and soot particle concentration.


2019 ◽  
Vol 9 (22) ◽  
pp. 4933 ◽  
Author(s):  
Sergej Bock ◽  
Christian Kijatkin ◽  
Dirk Berben ◽  
Mirco Imlau

This paper addresses the challenging task of optical characterization of pure, dielectric (nano-)powders with the aim to provide an end-to-end instruction from appropriate sample preparation up to the determination of material remission and absorption spectra. We succeeded in establishing an innovative preparation procedure to reproducibly obtain powder pellet samples with an ideal Lambertian scattering behavior. As a result, a procedure based on diffuse reflectance spectroscopy was developed that allows for (i) performing reproducible and artifact-free, high-quality measurements as well as (ii) a thorough optical analysis using Monte Carlo and Mie scattering simulations yielding the absorption spectrum in the visible spectral range. The procedure is valid for the particular case of powders that can be compressed into thick, non-translucent pellets and neither requires embedding of the dielectric (nano-)powders within an appropriate host matrix for measurements nor the use of integrating spheres. The reduced spectroscopic procedure minimizes the large number of sources for errors, enables an in-depth understanding of non-avoidable artifacts and is of particular advantage in the field of material sciences, i.e., for getting first insights to the optical features of a newly synthesized, pure dielectric powder, but also as an inline inspection tool for massively parallelised material characterization.


Sign in / Sign up

Export Citation Format

Share Document