Nonreciprocal extraordinary optical transmission through subwavelength slits in metallic film

Abstract

We demonstrate the phenomenon of nonreciprocal extraordinary optical transmission (NEOT) through metallic film with slits on the substrate of magneto-optical materials. Under uniformly magnetization, the system can show nonreciprocal transmission at near-IR frequency range. With a properly designed structure, the nonreciprocity can be as high as 57.6%. Numerical evidence shows that the nonreciprocal performance is sensitive to the incidence angle, as well as to the thickness of the substrate.

Guided modes in magneto-optical waveguides and the role in resonant transmission

“…Magneto-optical (MO) effect is then utilized for this purpose, in which the permittivity tensor of a MO medium is tunable by applying an external magnetic field. Great efforts have been devoted to the novel optical phenomena in subwavelength nanostructures with MO constituent [1][2][3][4][5][6][7][8]. It is shown that the MO effect can manipulate the characteristics of the extraordinary optical transmission (EOT) in metamaterials [1][2][3][4][5][6], not only change the wavelengthes of resonant transmission peaks, but also enhance the MO Faraday and Kerr effects.…”

“…It is shown that the MO effect can manipulate the characteristics of the extraordinary optical transmission (EOT) in metamaterials [1][2][3][4][5][6], not only change the wavelengthes of resonant transmission peaks, but also enhance the MO Faraday and Kerr effects. Nonreciprocal properties, including nonreciprocal dispersion and one-way EOT, have also been discussed [7,8].…”

“…The emergence of these unique MO characteristics is closely related to the nonzero offdiagonal elements in the permittivity tensor under the action of an external static magnetic B [8][9][10]. On one aspect, nonzero off-diagonal elements imply that the MO medium is anisotropic.…”

“…By using a polarizer element to select the finally transmitted polarization, the transmittance of a incident light wave is determined by the direction and magnitude of B. On the other aspect, the MO effect breaks the time-reversal symmetry and leads to the emergency of nonreciprocal effects [8][9][10]. For example, for a surface light wave localized at a MO-metal interface [9], its propagation is determined by the right-handed orthogonal vector triplet of (n, B, k), where n is the normal of the interface (from the metal toward the MO medium), B is the direction of the static magnetic field, and k is the wavevector, see Fig.…”

Surface magneto plasmons and their applications in the infrared frequencies

“…So far, there are two main ways to solve this problem. The first one is using composite materials, including metals and ferromagnetic materials, such as Ni and Co [55][56][57][58][59][60][61][62]. Using this method, due to the strong magnetization of the ferromagnetic materials, the applied magnetic field can be as weak as several ∼mT.…”