Asymmetric transmission of surface plasmon polaritons on planar gratings

V Kuzmiak,A A Maradudin

doi:10.1103/physreva.92.053813

Abstract

We describe a surface structure consisting of a metal-air interface where the metallic part consists of two metallic segments with a periodic modulation of the interface between them. Such a structure possesses a different transmissivity for a surface plasmon polariton incident on it from one side of it than it has for a surface plasmon polariton incident on it from the opposite side. This asymmetric transmission of a surface plasmon polariton is based on the suppression of the zero-order Bragg beam which, for a certain value of the modulation depth, is not transmitted through the structure, while the diffraction efficiencies of the +1 and -1 Bragg beams can be modified by varying the period of grating and/or the angle of incidence. For a certain range of the incidence angle one can observe asymmetry in transmittance for the -1 mode while the +1 mode is completely suppressed. By varying the material and geometrical parameters of the diffractive structure one can control the contrast transmission that characterizes the degree of the asymmetry. This property of the structure is demonstrated by the results of computer simulation calculations.

Highlights

In recent years there has been growing interest in investigations of two-dimensional nanostructured metallic structures
By varying the material and geometrical parameters of the diffractive structure one can control the contrast transmission that characterizes the degree of the asymmetry
A key idea underlying asymmetric transmission in such a planar grating structure is the suppression of the zero-order Bragg mode in a certain frequency range, which occurs at a given wavelength for the critical value of the modulation depth ζ0 given by Eq(17)

Summary

INTRODUCTION

In recent years there has been growing interest in investigations of two-dimensional nanostructured metallic structures. We have shown recently [7] that a 2D system consisting of a square array of scatterers deposited on a metal surface in a triangular mesh exhibits asymmetric transmission of a SPP when a diffractive structure is added to one side of the structure This structure does not require either electrical nonlinearity or the presence of the magnetic field to accomplish this. The suppression of the zero-order transmitted beam has been used effectively by Serebryannikov and his colleauges in designing structures that produce asymmetric transmission of volume electromagnetic waves through them [9]- [11] These are all slabs whose two surfaces are both periodically corrugated, but with different periods, and in some cases pierced by a slit of subwavelength width. This property of the structure is demonstrated by the results of computer simulation calculations

THEORETICAL MODEL

RESULTS

Normal incidence

Oblique incidence

CONCLUSION