Broadband gradient refractive index planar lens based on a compound liquid medium

Han, Haoxue; Wu, Lingling; Tian, Xiaoyong; Li, Dichen; Yin, Ming; Wang, Yu

doi:10.1063/1.4769344

Cited by 17 publications

(7 citation statements)

References 22 publications

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“…28,29 However, this phenomenon is very sensitive to large oblique incident angles, limiting further development. Gradient-index structures could also be utilized for broadband antireflection, 25,26 planar lens, 30,31 and broadband asymmetric transmission. 27 To achieve gradient-index structures, people have employed the phononic crystals with spatially varying filling fractions.…”

Section: Broadband Enhanced Transmission Of Acoustic Waves Through Sementioning

confidence: 99%

Broadband enhanced transmission of acoustic waves through serrated metal gratings

Deng

Xü

et al. 2015

Applied Physics Letters

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In this letter, we have demonstrated that serrated metal gratings, which introduce gradient coatings, can give rise to broadband transmission enhancement of acoustic waves. Here, we have experimentally and theoretically studied the acoustic transmission properties of metal gratings with or without serrated boundaries. The average transmission is obviously enhanced for serrated metal gratings within a wide frequency range, while the Fabry-Perot resonance is significantly suppressed. An effective medium hypothesis with varying acoustic impedance is proposed to analyze the mechanism, which was verified through comparison with finite-element simulation. The serrated boundary supplies gradient mass distribution and gradient normal acoustic impedance, which could efficiently reduce the boundary reflection. Further, by increasing the region of the serrated boundary, we present a broadband high-transmission grating for wide range of incident angle. Our results may have potential applications to broadband acoustic imaging, acoustic sensing, and acoustic devices. V

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Section: Broadband Enhanced Transmission Of Acoustic Waves Through Sementioning

confidence: 99%

Broadband enhanced transmission of acoustic waves through serrated metal gratings

Deng

Xü

et al. 2015

Applied Physics Letters

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“…From the experimental perspective, the critical requirement for observing the proposed WSL is to fabricate the dielectrics with designed refractive index = (1 + ) . The feasible technique route of well-controlling refractive index or dielectric constant is to employ composite material whose permittivity can be fine-tuned by the component concentration according to effective medium theory [29][30][31]. The composite suitable to our model may be the plastic foam where the porosity (air concentration) can be engineered to realize the desired dielectrics.…”

Section: Whenmentioning

confidence: 99%

Photonic Wannier-Stark Ladder from Coupled Electromagnetic Cavities

Anwar

et al. 2015

International Journal of Antennas and Propagation

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We have investigated the photonic Wannier-Stark ladder in the system of coupled electromagnetic cavities, which consists of a stack of metallic plates structured with subwavelength apertures and where the tilted potential effect is mimicked by imposing the gradient variation of refractive index. Making an analogy to its quantum counterpart and assuming the translational property of its solutions, we have shown the photonic ladder has the eigenenergies, that is, frequencies, in a geometrical series. Within the approximation of small gradient, the ladder states manifest the equidistant frequency spacing in the spectrum. By both analytical derivation and numerical simulation, we have illustrated the geometrically progressed energies of the photonic Wannier-Stark ladder.

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“…[4][5][6] It has now evolved into a powerful tool for designing a wide variety of new devices. [7][8][9][10][11][12] The most remarkable example is the invisibility cloak which has attracted great attention from researchers. [13][14][15] The acoustic invisibility cloak can make objects hard to detect acoustically.…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of the trapeziform and flat acoustic cloaks with controllable invisibility performance in a quasi-space

et al. 2015

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We present the design, implementation and detailed performance analysis for a class of trapeziform and flat acoustic cloaks. An effective large invisible area is obtained compared with the traditional carpet cloak. The cloaks are realized with homogeneous metamaterials which are made of periodic arrangements of subwavelength unit cells composed of steel embedded in air. The microstructures and its effective parameters of the cloaks are determined quickly and precisely in a broadband frequency range by using the effective medium theory and the proposed parameters optimization method. The invisibility capability of the cloaks can be controlled by the variation of the key design parameters and scale factor which are proved to have more influence on the performance in the near field than that in the far field. Different designs are suitable for different application situations. Good cloaking performance demonstrates that such a device can be physically realized with natural materials which will greatly promote the real applications of invisibility cloak.

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Broadband gradient refractive index planar lens based on a compound liquid medium

Cited by 17 publications

References 22 publications

Broadband enhanced transmission of acoustic waves through serrated metal gratings

Broadband enhanced transmission of acoustic waves through serrated metal gratings

Photonic Wannier-Stark Ladder from Coupled Electromagnetic Cavities

Design and analysis of the trapeziform and flat acoustic cloaks with controllable invisibility performance in a quasi-space

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