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Seoul, South Korea

Jin X.-R.,Hanyang University | Lu Y.,Hanyang University | Lu Y.,Ningbo Institute of Materials Technology and Engineering | Zheng H.,Hanyang University | And 4 more authors.
Optics Communications | Year: 2011

Using only two gold strips, we propose a scheme for generation of the plasmonic analogue of electromagnetically-induced transparency (EIT) in stacked optical metamaterials by utilizing the second-order plasmon resonance. In addition, we show that the plasmonic EIT can be achieved with asymmetric structure, since the asymmetric structure allows the excitation of the dark mode. © 2011 Elsevier B.V.

Lee Y.P.,Hanyang University | Tuong P.V.,Hanyang University | Zheng H.Y.,Hanyang University | Rhee J.Y.,Sungkyunkwan University | Jang W.H.,Electromagnetic Wave Institute
Journal of the Korean Physical Society | Year: 2012

We studied structures that describe the perfect-absorber effect by using different mechanisms. Firstly, we investigated the dependences of the reflectance and the absorbance of a metamaterial, as structure proposed by Landy et al. [Phys. Rev. Lett. 100, 207402 (2008)] on gap 'g' of the structure at GHz frequencies. The value of the gap was obtained, which gives the maximum absorbance and the minimum reflectance. In addition, the change of geometry of the electric ring resonance as an I-shape made the reflectance disappear at the resonance frequency. A narrow-band peak of the perfect-absorber effect, which was enhanced to be greater than 99.5% at 13.5 GHz, was observed by using a multilayer model for the simplified absorber structure. Secondly, we investigated an absorber structure that includes two metal layers, periodic cut-wire bars at the front and a copper plane at the back, separated by a dielectric layer. The results showed that the absorbance and the resonance frequency of this structure strongly depended on the thickness and the length of the cut-wire bar, respectively. Base on these, we successfully designed a broad-band absorber structure by arranging cut-wire bars with different lengths appropriately in a "meta-atom".

Tuong P.V.,Hanyang University | Tuong P.V.,Vietnam Academy of Science and Technology | Park J.W.,Hanyang University | Rhee J.Y.,Sungkyunkwan University | And 4 more authors.
Applied Physics Letters | Year: 2013

We numerically and experimentally investigated dual-band absorption of sandwich-structure metamaterials which include periodic metal coupled rings at the front separated from the metal plane at the back by a dielectric layer. The properties are demonstrated in both GHz and mid-IR regimes of electromagnetic (EM) wave. The dual-band perfect absorber with polarization independence is observed under normal incidence. In order to understand the EM properties of dual-band perfect absorber, the plasmonic excitation was clarified for both peaks. Finally, by connecting the rings, the perfect-absorption peaks can be controlled with the polarization angle of incident EM wave. © 2013 American Institute of Physics.

Park J.W.,Hanyang University | Tuong P.V.,Hanyang University | Rhee J.Y.,Sungkyunkwan University | Kim K.W.,Sun Moon University | And 4 more authors.
Optics Express | Year: 2013

We propose multi-band metamaterial absorbers at microwave frequencies. The design, the analysis, the fabrication, and the measurement of the absorbers working in multiple bands are presented. The numerical simulations and the experiments in the microwave anechoic chamber were performed. The metamaterial absorbers consist of an delicate arrangement of donut-shape resonators with different sizes and a metallic background plane, separated by a dielectric. The near-perfect absorptions of dual, triple and quad peaks are persistent with polarization independence, and the effect of angle of incidence for both TE and TM modes was also elucidated. It was also found that the multiple-reflection theory was not suitable for explaining the absorption mechanism of our investigated structures. The results of this study are promising for the practical applications. © 2013 Optical Society of America.

Jin X.-R.,Hanyang University | Park J.,Hanyang University | Zheng H.,Hanyang University | Lee S.,Hanyang University | And 5 more authors.
Optics Express | Year: 2011

Using a planar metamaterial, which consists of two silver strips, we theoretically demonstrate the plasmonic electromagnetically-induced transparency (EIT)-like spectral response at optical frequencies. The two silver strips serve as the bright modes, and are excited strongly by the incident wave. Based on the weak hybridization between the two bright modes, a highly-dispersive plasmonic EIT-like spectral response appears in our scheme. Moreover, the group index is higher than that of another scheme which utilizes the strong coupling between the bright and dark modes. © 2011 Optical Society of America.

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