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Wang B.-X.,Jiangnan University | Wang G.-Z.,Modern Educational Technology Center | Wang L.-L.,Hunan University

We present a novel dual-band terahertz absorber formed by only a patterned U-shaped metallic ring and a metallic ground plane separated by a dielectric layer. Theoretical results show that the proposed absorber has two distinct absorption bands whose peaks are average over 98 %. Different from previous reports by combining the resonances of the complex structure (coplanar super-unit structure or stacked structure) to obtain the dual-band response, the proposed structure utilizes the LC resonance and dipolar response of the single patterned structure and thus making the proposed structure quite easy to be fabricated. The roles of the geometric parameters are investigated to explain the principle of absorption. Furthermore, the proposed concept applies to other types of absorber structure and can be readily extended to other frequency regimes for a host of applications such as detection, imaging, sensing, and selective thermal emitters. © 2015, Springer Science+Business Media New York. Source

Hu F.,Chongqing University | Li M.,Chongqing Normal University | Zhang Y.N.,Nanjing Gulou Vocational School | Peng T.,Chongqing University | Lei Y.,Modern Educational Technology Center
Lecture Notes in Electrical Engineering

A news web page has lot of words, most of which exist in topic zones, and the rest in noise zones. According to this feature, we propose a novel approach to purify webpages. Without site template and based on word density, it can purify isomorphic pages, nonisomorphic pages, and pages not meeting XML specification. The test proves it as satisfactory and stable. © 2013 Springer-Verlag. Source

Wang B.-X.,Jiangnan University | Wang G.-Z.,Modern Educational Technology Center | Sang T.,Jiangnan University
Journal of Physics D: Applied Physics

For a general metamaterial absorber, single patterned structure has only one resonance absorption peak. Therefore, a multi-band perfect absorber can be obtained by employing multiple different-sized metallic patterns. However, this kind of design strategy removes the novelty of their resonance mechanism and is also quite troublesome in regard to fabrication. Here, a novel and simple design of a triple-band terahertz absorber formed by only an asymmetric cross is presented. Theoretical results show that the proposed structure has three distinct absorption bands whose peaks are all over 99%. The first two absorption peaks are due to the magnetic resonances of the different sections of the asymmetric cross, and the third peak is based on the surface response of the structure. Moreover, sensing performance of the absorber is investigated in terms of the surrounding index. It is found that the figure of merit and quality factor of the third peak is much larger than those of the first two peaks, which reveals the proposed absorber's, in particular the third resonance mode of the metamaterial, potential applications in sensing and detection. © 2016 IOP Publishing Ltd. Source

Wang B.-X.,Hunan University | Wang B.-X.,Jiangnan University | Wang G.-Z.,Modern Educational Technology Center | Zhai X.,Hunan University | Wang L.-L.,Hunan University
IEEE Photonics Journal

Metamaterial-based perfect absorbers have attracted considerable attention due to their potential for practical applications. The existing absorbers, however, are mostly polarization insensitive or only sensitive to one direction, which is inapplicable in some areas. Polarization tunable or high absorption in two orthogonal directions is very useful and necessary. Herein, we present a polarization tunable absorber formed by an asymmetric patch and a dielectric layer on top of a metallic board. With this structure, the frequency of the absorber can be tuned by merely changing the polarization of the incident. The tunable mechanism originates from the different length of the patch along the two orthogonal directions. The concept is rather general and applicable to various absorbers, as long as the asymmetric design is valid. The absorber can find practical applications in manipulation of the polarization of the light and detecting waves with specific polarization. © 2009-2012 IEEE. Source

Wang G.-Z.,Modern Educational Technology Center | Wang B.-X.,Jiangnan University
Journal of Lightwave Technology

A novel and simple design of five-band terahertz absorber is investigated. This absorber consists of a four-gap comb resonator and a dielectric slab on top of a metallic board. The simulation results show that the structure has five distinct absorption peaks, each with the absorption of over 98%. Multiband absorption property can be explained by the overlapping of the LC resonances, dipolar response, and high-order resonance of the structure. Moreover, the design gives considerable freedom to shift or change the frequencies of the absorber by varying the arm lengths of the comb. The proposed absorber has potential applications in detection, imaging, and sensing. © 1983-2012 IEEE. Source

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