Numerical Analysis of Enhanced Transmission Through a Single Subwavelength Aperture Based on Mie Resonance Single Particle

Abstract

Abstract-We numerically demonstrate that the transmission through a deep subwavelength (λ 0 /20) aperture in a metal plate could be greatly enhanced owing to the resonance effects of a high permittivity (κ) dielectric cube tightly coupled to the aperture. The transmission enhancement originates from the confinement and reradiation of the electromagnetic energy impinging onto the high κ cube which operates in the 1st Mie resonance mode, and behaves as an ultra-small magnetic dipole antenna. The complex permittivity of the cube governs the operating frequency and the enhancement in terms of bandwidth and transmissivity maximum. Additionally, based on the isotropic response of the high κ cube with dimensions comparable to the aperture size, the almost independence of the enhancement properties on the illumination polarization and incidence angle was assessed.

Near-field probing of Mie resonances in single TiO_2 microspheres at terahertz frequencies

“…The localized field couples through the sub-wavelength aperture more efficiently than the incident THz beam, resulting in enhanced transmission at the frequency of the Mie resonance. Recent numerical studies showed that the power transmission through a λ/20 aperture can be enhanced by up to 50 times when the dielectric resonator is positioned in front of the aperture [24]. This effect was utilized to probe a dielectric cube resonator at microwave frequencies [22].…”

Resonant Transmission Through a Pair of Ridge-Loaded Circular Sub-Wavelength Apertures

“…It was found that the transmittance normalized to the area for small circular aperture scales as (a/λ) 4 where a is the aperture radius and λ is the wavelength and, therefore, the transmittance decreases abruptly as the aperture radius reduces [1]. To solve this problem, various approaches have been introduced [2,3], and numerous research results in the microwave area have also been reported recently [4][5][6][7][8][9][10].…”

“…Representative methods to enhance the transmittance through a small aperture are to modify the shape of the aperture into some self-resonant shapes such as C-shaped or H-shaped apertures [2][3][4][5][6], to place a dielectric or conducting object close to a sub-wavelength aperture [7,8], and to surround the aperture with grooves [9][10][11]. Recently, metamaterials have been employed to make the small aperture resonant [12].…”

Investigation of Fano Resonances Induced by Higher Order Plasmon Modes on a Circular Nano-Disk With an Elongated Cavity

“…These specific dimensions allow generation of dipolar and quadrupolar modes (which destructively interfere to induce Fano resonances) within the visible part of the spectrum. It should be mentioned here that as long as the overall size of the disk is a fraction of the wavelength, scaling the geometric parameters of the design (i.e., keeping their ratio the same) does not significantly change the response of the system (for example see [51,52] for a detailed discussion on the effect of scaling on the optical response of a hole in a metal film). In this work, D, L, and W are large enough to allow for generation of higher-order modes and also small enough to avoid large phase retardation effects, which is well-known to complicate the design of the structure.…”