Scattering from a gyrotropic cylinder

Palais, Joseph C.

doi:10.1109/tap.1963.1138053

Cited by 15 publications

(15 citation statements)

References 3 publications

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“…The validity of our calculations is confirmed by comparison with HFSS commercial software. The blue dots depict results for Q sc /(πR 2 2 ) obtained via HFSS simulations, thus establishing a good agreement with the VIE. It should be mentioned that an excellent agreement can be met, especially for the localized surface plasmon (LSP) appearing at λ b /R 2 9.92, but it would require a tremendous amount of CPU time for HFSS to extract the spectrum using its finite element solver.…”

Section: Engineering Functional Spherical Terahertz Antennas For Diresupporting

confidence: 70%

“…In the analysis that follows, we demonstrate a state which corresponds to forward-scattering in the absence of magnetic field, and to back-scattering with non-zero external magnetic bias. Figure 2A depicts the normalized scattering cross section Q sc /(πR 2 2 ) versus the normalized wavelength λ b /R 2 , under null magnetic field, for outer radius value R 2 10 μm, and R 1 /R 2 0.9. In addition to the full-wave contribution to Q sc -i.e., all spherical harmonics and angular momentum terms, required for convergence, contribute in Eq.…”

Section: Engineering Functional Spherical Terahertz Antennas For Dirementioning

confidence: 99%

“…Magneto-optical materials have been successfully employed in cylindrical structures, such as infinite cylinders or arrays of such. In particular, their use was recently achieved in the context of active scattering, via the available Mie theory for infinite, two-dimensional circular gyroelectric/gyromagnetic cylinders whose solution can be separated into TE and TM modes [2]. Specifically, active control of directional scattering with a core-shell infinite cylinder driven by an external magnetic field, as well as in cylindrical reconfigurable meta-lattices, has been theoretically examined by breaking the degeneracy of the multipoles in the subwavelength regime, thereby allowing the splitted modes to interfere and lead to directional optical switching [3,4].…”

Section: Introductionmentioning

confidence: 99%

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Magnetic switching of Kerker scattering in spherical microresonators

et al. 2020

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AbstractMagneto-optical materials have become a key tool in functional nanophotonics, mainly due to their ability to offer active tuning between two different operational states in subwavelength structures. In the long-wavelength limit, such states may be considered as the directional forward- and back-scattering operations, due to the interplay between magnetic and electric dipolar modes, which act as equivalent Huygens sources. In this work, on the basis of full-wave electrodynamic calculations based on a rigorous volume integral equation (VIE) method, we demonstrate the feasibility of obtaining magnetically-tunable directionality inversion in spherical microresonators (THz antennas) coated by magneto-optical materials. In particular, our analysis reveals that when a high-index dielectric is coated with a magneto-optical material, we can switch the back-scattering of the whole particle to forward-scattering simply by turning off/on an external magnetic field bias. The validity of our calculations is confirmed by reproducing the above two-state operation, predicted by the VIE, with full-wave finite-element commercial software. Our results are of interest for the design of state-of-the-art active metasurfaces and metalenses, as well as for functional nanophotonic structures, and scattering and nanoantennas engineering.

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Section: Engineering Functional Spherical Terahertz Antennas For Diresupporting

confidence: 70%

Section: Engineering Functional Spherical Terahertz Antennas For Dirementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Magnetic switching of Kerker scattering in spherical microresonators

et al. 2020

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“…However, for the well-known practical G-type materials [7], having permittivity and permeability tensors defined in a Cartesian coordinate system denoted by ζ = ζ 0 ζ r for ζ = ε, μ with tensor elements ζ xx = ζ yy , ζ yx = −ζ xy , and all the other tensor elements except ζ zz being zero and of which gyrotropic [1], [2], [35], [36] is a special case when ζ xy is purely imaginary, one can still obtain expressions for the electric and magnetic fields within the elliptic cylinder in the form of infinite series involving Mathieu functions as shown in Appendix B, and thereby a formal series solution to the associated scattering problem. This is as a result of the tensor elements ζ τσ in the Cartesian coordinate system for τ = x, y, z and σ = x, y, z as in (A18), transforming into the corresponding elements ζ τσ in the elliptic coordinate system for τ = u, v, z and σ = u, v, z as in (A19).…”

Section: Fields Within the Coatingmentioning

confidence: 99%

“…Consequently, a series solution to the problem of scattering of a transverse magnetically polarized incident plane wave by an anisotropic elliptic cylinder composed of a G-type material can also be obtained, which includes gyrotropic [1], [2], [35], [36] as well as gyromagnetic [41]- [44] materials, as special cases.…”

Section: Appendix Bmentioning

confidence: 99%

Scattering of a Plane Wave by a Homogeneous Anisotropic Elliptic Cylinder

Hamid

Cooray

2015

IEEE Trans. Antennas Propagat.

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A formal series solution to the problem of scattering of a normally incident plane wave from an infinite homogeneous anisotropic elliptic cylinder is presented. The formulation of the problem is accomplished by assuming that the permittivity and the permeability tensors of the anisotropic material referred to the elliptic cylindrical coordinate axes are mainly biaxial and diagonal, and expanding each field associated with the problem in terms of a series of suitable Mathieu functions and expansion coefficients. The incident field expansion coefficients are known, but those associated with the scattered and transmitted fields are unknown. The unknown expansion coefficients are obtained by imposing appropriate boundary conditions at the surface of the anisotropic cylinder. Numerical results are presented as normalized bistatic and backscattering widths for elliptic cylinders of different sizes and permeabilities to show the effects of the material anisotropy on scattering.

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Complex WGM frequencies of gyroelectric cylindrical resonators

Katsinos

Zouros

Kolezas

et al. 2021

IET Microwaves Antenna & Prop

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Asymptotic closed-form expressions for calculating complex transverse electric (TE)/ transverse magnetic (TM) whispering gallery mode (WGM) frequencies in homogeneous gyroelectric circular cylindrical resonators of infinite length are derived. In addition, a volume integral equation (VIE)-cylindrical Dini series expansion method is extended to support the prediction of complex WGMs for continuously varying highly inhomogeneous gyroelectric circular cylindrical resonators. To this end, the entire domain orthogonal vectorial basis of VIE is extended to support very large indices of the involved Dini-type cylindrical vector wave functions via asymptotic closed-form expressions. This way, the eigenbasis required to solve the VIE becomes free of numerical instabilities arising when very large orders of the involved Bessel functions are employed. The complex frequencies obtained by the asymptotic closed-form expressions for the case of the homogeneous gyroelectric resonator, as well as those obtained by the VIE when the multilayered gyroelectric resonator is reduced to one layer, are validated by comparisons with the complex roots extracted by numerically solving the TE/TM characteristic equations obtained from the separation of variables method, using complex root finding techniques. We demonstrate the calculation of very highorder WGM frequencies for cylindrical resonators composed of homogeneous and highly inhomogeneous permittivity profiles. This asymptotic theory constitutes a rigorous tool that may serve for verifying method of analytical regularisation-based numerical solutions for other non-circular inhomogeneous cylinders, and for interpreting experimental data for applications such as WGM lasing, refractometric sensing, and magneto-optic coupling.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

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Scattering from a gyrotropic cylinder

Cited by 15 publications

References 3 publications

Magnetic switching of Kerker scattering in spherical microresonators

Magnetic switching of Kerker scattering in spherical microresonators

Scattering of a Plane Wave by a Homogeneous Anisotropic Elliptic Cylinder

Complex WGM frequencies of gyroelectric cylindrical resonators

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