Unidirectional transmission in non-symmetric gratings containing metallic layers

Abstract

Abstract:The mechanism of achieving unidirectional transmission in the gratings, which only contain isotropic dielectric and metallic layers, is suggested and numerically validated. It is shown that significant transmission in one direction and nearly zero transmission in the opposite direction can be obtained in the same intrinsically isotropic gratings as those studied recently in A. E. Serebryannikov and E. Ozbay, Opt. Express 17, 278 (2009), but at a non-zero angle of incidence. The tilting, non-symmetric features of the grating and the presence of a metallic layer with a small positive real part of the index of refraction are the conditions that are necessary for obtaining the unidirectionality. Single-and multibeam operational regimes are demonstrated. The frequency and angle ranges of the unidirectional transmission can be estimated by using the conventional framework based on isofrequency dispersion contours and construction lines that properly take into account the periodic features of the interfaces, but should then be corrected because of the tunneling arising within the adjacent ranges. After proper optimization, this mechanism is expected to become an alternative to that based on the use of anisotropic materials. (IEE, London, 1999). 2009 Optical Society of America

Basics of the photonic crystal gratings

“…In the gratings made of Drude metals or composites, the actual thresholds have different locations as compared to the classical case that is associated with dielectric gratings (Serebryannikov & Ozbay, 2009). In the PCGs with either dielectric or metallic rods, the actual thresholds can also be affected by location of the stop bands of the PC (Serebryannikov, 2006;Serebryannikov, 2009).…”

Controlling surface plasmon polaritons by a static and/or time-dependent external magnetic field

“…In several papers published recently [20][21][22][23][24] authors claimed nonreciprocity on the basis of various effects observed in the behavior electromagnetic propagation in linear, time-independent structures consisting of materials described by symmetric (i.e. reciprocal) permittivities and/or permeabilities.…”

“…[25] that in the interpretation of the behavior observed in silicon photonic circuit based on asymmetric mode conversion observed experimentally [24] the term "nonreciprocal" has been used incorrectly. Based on the validity of the Lorentz nonreciporocity theorem statement we believe that the interpretation of the effects observed in Refs.…”

Manipulation of Asymmetric Transmission in Planar Chiral Nanostructures by Anisotropic Loss

“…Meanwhile, there were attempts to achieve asymmetric but still reciprocal transmission by using conventionally isotropic, linear, and lossy or lossless materials. For instance, the asymmetric transmission of linearly polarized waves can be realized by using diffractive nonsymmetrical volumetric gratings based on photonic crystals or metals, [ 6 ] using nonsymmetrical two layered metallic structures, [ 7 ] using nonsymmetrical metallic gratings supporting surface plasmons, [ 8 ] and using dielectric gratings. [ 9 ] The asymmetric transmission of circularly polarized waves has been demonstrated at normal incidence by using a multilayered structure [ 7,10 ] and by using a planar chiral structure (PCS) consisting of single layer of metaatoms.…”