Resonant transmission of electromagnetic fields through subwavelength zero-ϵslits

Abstract

We theoretically investigate the transmission of electromagnetic radiation through a metal plate with a zero-⑀ metamaterial slit, where the permittivity tends towards zero over a given bandwidth. Our analytic results demonstrate that the transmission coefficient can be substantial for a broad range of slit geometries, including subwavelength widths that are many wavelengths long. This resonant effect has features quite unlike the Fabry-Perot-like resonances that have been observed in conductors with deep channels. We further reveal that ultranarrow zero-⑀ channels can have significantly greater transmission compared to slits with no wave impedance difference across them.

Dirac Dispersion in Two-Dimensional Photonic Crystals

“…While previous attention may have been focused on realizing metamaterials with negative refractive indices, materials that have zero refractive indices are equally interesting. As n 2 = εμ, a zero-refractive-index material can have either single zero (ε eff = 0 or μ eff = 0) or double zero (ε eff = μ eff = 0) [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64]. There is no phase variance in the wave transport process inside a zero-index material.…”

“…There is no phase variance in the wave transport process inside a zero-index material. This leads to many peculiar properties such as the tunneling of electromagnetic waves through subwavelength channels and bends [49][50][51][52][53][54][55][56][57], the tailoring of the radiation phase pattern of arbitrary sources [58][59][60], and the cloaking of objects inside a channel with specific boundary conditions [61][62][63][64]. The tunneling phenomenon has been demonstrated experimentally using complementary split ring resonators at the microwave frequency [55].…”

Review of mid-infrared plasmonic materials

“…An electromagnetic wave propagating within an ENZ material will exhibit a dramatic increase in local wavelength (as the refractive index becomes vanishingly small). Such materials have been of significant recent interest, resulting in large part from simulation and theory, as well as microwave frequency experimental, results suggesting that ENZ materials can allow for near perfect coupling between waveguiding structures, 46,47 or control of radiating phase patterns, 48 among other novel effects. 49 The majority of ENZ experimental demonstrations have been performed at microwave frequencies, where composite materials or waveguiding structures can be designed to mimic bulk ENZ behavior.…”

Funneling Light through a Subwavelength Aperture with Epsilon-Near-Zero Materials

“…In particular, the electromagnetic field inside the ENZ structures tends to become completely homogeneous, reflecting the dramatic extension of local wavelength caused by a vanishingly small refractive index. It has been shown theoretically [10,11] that lossless ENZ systems may yield perfect coupling between two planar waveguides through an ultra-thin guiding channel. Experimental verifications of this principle, in the microwave regime, utilized split ring resonator structures [12] or alternatively, waveguides designed to mimic the optical properties of an ENZ material [11,13].…”