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Anisotropy modeling of terahertz metamaterials: polarization dependent resonance manipulation by meta-atom cluster.

Jung H, In C, Choi H, Lee H - Sci Rep (2014)

Bottom Line: Most metamaterials are known to have anisotropic properties, but existing anisotropy models are applicable only to a single meta-atom and its properties.Here we propose an anisotropy model for asymmetrical meta-atom clusters and their polarization dependency.The proposed anisotropic meta-atom clusters show a unique resonance property in which their frequencies can be altered for parallel polarization, but fixed to a single resonance frequency for perpendicular polarization.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Electronic Engineering, Soongsil University, Seoul 156-743, Korea [2].

ABSTRACT
Recently metamaterials have inspired worldwide researches due to their exotic properties in transmitting, reflecting, absorbing or refracting specific electromagnetic waves. Most metamaterials are known to have anisotropic properties, but existing anisotropy models are applicable only to a single meta-atom and its properties. Here we propose an anisotropy model for asymmetrical meta-atom clusters and their polarization dependency. The proposed anisotropic meta-atom clusters show a unique resonance property in which their frequencies can be altered for parallel polarization, but fixed to a single resonance frequency for perpendicular polarization. The proposed anisotropic metamaterials are expected to pave the way for novel optical systems.

No MeSH data available.


Related in: MedlinePlus

Experimental results of H-shaped meta-atom cluster arrays.(a) Optical microscopy images of our fabricated H-shaped meta-atom clusters with different numbers (single, double, triple, and quad) of H-shaped unit cells. Measured and simulated transmission spectra of the proposed H-shaped metamaterials (b) for parallel polarization and (c) for perpendicular polarization.
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f5: Experimental results of H-shaped meta-atom cluster arrays.(a) Optical microscopy images of our fabricated H-shaped meta-atom clusters with different numbers (single, double, triple, and quad) of H-shaped unit cells. Measured and simulated transmission spectra of the proposed H-shaped metamaterials (b) for parallel polarization and (c) for perpendicular polarization.

Mentions: However, the higher resonance frequency components for parallel polarization still exist near the fixed resonance frequency (ωc) for perpendicular polarization, working as spectral noise for utilizing the undisturbed ωc. Therefore, to design the resonance frequencies of anisotropic metamaterials that can be altered for parallel polarization but completely fixed for perpendicular polarization (shown in Figure 5), we designed H-shaped meta-atom clusters that can maintain a symmetric current path for parallel polarization. The single H-shaped anisotropic meta-atom and its clusters (double, triple, and quad) act like identical CW unit cells, and the induced current also has a completely symmetric current path for parallel polarization. Their characteristic resonance frequencies can be estimated bywhere ceff is the speed of light divided by an effective refractive index, l and h are the center bar length and the side line height of the H-shaped meta-atom, respectively. n is the number of H-shaped meta-atoms in the proposed meta-atom clusters. These equations show that ωc is independent of n and therefore constant, while the ωf absolutely depends on n.


Anisotropy modeling of terahertz metamaterials: polarization dependent resonance manipulation by meta-atom cluster.

Jung H, In C, Choi H, Lee H - Sci Rep (2014)

Experimental results of H-shaped meta-atom cluster arrays.(a) Optical microscopy images of our fabricated H-shaped meta-atom clusters with different numbers (single, double, triple, and quad) of H-shaped unit cells. Measured and simulated transmission spectra of the proposed H-shaped metamaterials (b) for parallel polarization and (c) for perpendicular polarization.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048888&req=5

f5: Experimental results of H-shaped meta-atom cluster arrays.(a) Optical microscopy images of our fabricated H-shaped meta-atom clusters with different numbers (single, double, triple, and quad) of H-shaped unit cells. Measured and simulated transmission spectra of the proposed H-shaped metamaterials (b) for parallel polarization and (c) for perpendicular polarization.
Mentions: However, the higher resonance frequency components for parallel polarization still exist near the fixed resonance frequency (ωc) for perpendicular polarization, working as spectral noise for utilizing the undisturbed ωc. Therefore, to design the resonance frequencies of anisotropic metamaterials that can be altered for parallel polarization but completely fixed for perpendicular polarization (shown in Figure 5), we designed H-shaped meta-atom clusters that can maintain a symmetric current path for parallel polarization. The single H-shaped anisotropic meta-atom and its clusters (double, triple, and quad) act like identical CW unit cells, and the induced current also has a completely symmetric current path for parallel polarization. Their characteristic resonance frequencies can be estimated bywhere ceff is the speed of light divided by an effective refractive index, l and h are the center bar length and the side line height of the H-shaped meta-atom, respectively. n is the number of H-shaped meta-atoms in the proposed meta-atom clusters. These equations show that ωc is independent of n and therefore constant, while the ωf absolutely depends on n.

Bottom Line: Most metamaterials are known to have anisotropic properties, but existing anisotropy models are applicable only to a single meta-atom and its properties.Here we propose an anisotropy model for asymmetrical meta-atom clusters and their polarization dependency.The proposed anisotropic meta-atom clusters show a unique resonance property in which their frequencies can be altered for parallel polarization, but fixed to a single resonance frequency for perpendicular polarization.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Electronic Engineering, Soongsil University, Seoul 156-743, Korea [2].

ABSTRACT
Recently metamaterials have inspired worldwide researches due to their exotic properties in transmitting, reflecting, absorbing or refracting specific electromagnetic waves. Most metamaterials are known to have anisotropic properties, but existing anisotropy models are applicable only to a single meta-atom and its properties. Here we propose an anisotropy model for asymmetrical meta-atom clusters and their polarization dependency. The proposed anisotropic meta-atom clusters show a unique resonance property in which their frequencies can be altered for parallel polarization, but fixed to a single resonance frequency for perpendicular polarization. The proposed anisotropic metamaterials are expected to pave the way for novel optical systems.

No MeSH data available.


Related in: MedlinePlus