Limits...
Optical 'magnetic mirror' metasurfaces using interference between Fabry-Pérot cavity resonances in coaxial apertures.

Rajasekharan R, Roberts A - Sci Rep (2015)

Bottom Line: Conversely, we show that in the case of a perfect conductor, near-perfect, broadband reflection can be achieved with zero phase change in the electric field and a variation of 2π on passing through the coincident resonances.Extending the concept to shorter wavelengths, we show that mirrors exhibiting close to a 2π phase excursion, albeit with a reduction in the amplitude reflection coefficient at resonance and a lower Q, can be also achieved.Structures such as these can be used to enhance light-matter interactions at surfaces and act as high impedance ground planes for antenna applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Electronic Engineering, The University of Melbourne, Victoria, 3010, Australia.

ABSTRACT
Here we propose and computationally demonstrate a quasi-planar metasurface consisting of arrays of pairs of concentric coaxial apertures in a metallic film. The structure relies on destructive interference between Fabry-Pérot modes excited in each aperture at resonance producing transmitted fields that interfere destructively leading to suppressed transmission. Conversely, we show that in the case of a perfect conductor, near-perfect, broadband reflection can be achieved with zero phase change in the electric field and a variation of 2π on passing through the coincident resonances. Extending the concept to shorter wavelengths, we show that mirrors exhibiting close to a 2π phase excursion, albeit with a reduction in the amplitude reflection coefficient at resonance and a lower Q, can be also achieved. Structures such as these can be used to enhance light-matter interactions at surfaces and act as high impedance ground planes for antenna applications.

No MeSH data available.


Related in: MedlinePlus

Schematic showing (a) a hexagonal array of pairs of concentric coaxial apertures in a metal film and (b) a pair of concentric coaxial apertures with parameters used to describe the geometry.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4446991&req=5

f1: Schematic showing (a) a hexagonal array of pairs of concentric coaxial apertures in a metal film and (b) a pair of concentric coaxial apertures with parameters used to describe the geometry.

Mentions: Specifically, we here computationally investigate resonances of a hexagonal periodic arrangement of pairs of concentric coaxial apertures in a metallic film (Fig. 1). We consider separately the cases where the film is assumed to be, firstly, a perfect electric conductor (PEC) and, secondly, silver in the visible region of the electromagnetic spectrum. In the former case a modal method in the monomodal approximation is used, whereas a full-field Finite Element Method (FEM) solver is used to study apertures in silver films.


Optical 'magnetic mirror' metasurfaces using interference between Fabry-Pérot cavity resonances in coaxial apertures.

Rajasekharan R, Roberts A - Sci Rep (2015)

Schematic showing (a) a hexagonal array of pairs of concentric coaxial apertures in a metal film and (b) a pair of concentric coaxial apertures with parameters used to describe the geometry.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4446991&req=5

f1: Schematic showing (a) a hexagonal array of pairs of concentric coaxial apertures in a metal film and (b) a pair of concentric coaxial apertures with parameters used to describe the geometry.
Mentions: Specifically, we here computationally investigate resonances of a hexagonal periodic arrangement of pairs of concentric coaxial apertures in a metallic film (Fig. 1). We consider separately the cases where the film is assumed to be, firstly, a perfect electric conductor (PEC) and, secondly, silver in the visible region of the electromagnetic spectrum. In the former case a modal method in the monomodal approximation is used, whereas a full-field Finite Element Method (FEM) solver is used to study apertures in silver films.

Bottom Line: Conversely, we show that in the case of a perfect conductor, near-perfect, broadband reflection can be achieved with zero phase change in the electric field and a variation of 2π on passing through the coincident resonances.Extending the concept to shorter wavelengths, we show that mirrors exhibiting close to a 2π phase excursion, albeit with a reduction in the amplitude reflection coefficient at resonance and a lower Q, can be also achieved.Structures such as these can be used to enhance light-matter interactions at surfaces and act as high impedance ground planes for antenna applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Electronic Engineering, The University of Melbourne, Victoria, 3010, Australia.

ABSTRACT
Here we propose and computationally demonstrate a quasi-planar metasurface consisting of arrays of pairs of concentric coaxial apertures in a metallic film. The structure relies on destructive interference between Fabry-Pérot modes excited in each aperture at resonance producing transmitted fields that interfere destructively leading to suppressed transmission. Conversely, we show that in the case of a perfect conductor, near-perfect, broadband reflection can be achieved with zero phase change in the electric field and a variation of 2π on passing through the coincident resonances. Extending the concept to shorter wavelengths, we show that mirrors exhibiting close to a 2π phase excursion, albeit with a reduction in the amplitude reflection coefficient at resonance and a lower Q, can be also achieved. Structures such as these can be used to enhance light-matter interactions at surfaces and act as high impedance ground planes for antenna applications.

No MeSH data available.


Related in: MedlinePlus