scholarly journals Design and Fabrication of Negative-Refractive-Index Metamaterial Unit Cells for Near-Megahertz Enhanced Acoustic Transmission in Biomedical Ultrasound Applications

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Jiaying Wang ◽  
Florian Allein ◽  
Nicholas Boechler ◽  
James Friend ◽  
Oscar Vazquez-Mena
2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dragan Tanasković ◽  
Zoran Jakšić ◽  
Marko Obradov ◽  
Olga Jakšić

An important class of electromagnetic metamaterials are aperture-based metasurfaces. Examples include extraordinary optical transmission arrays and double fishnets with negative refractive index. We analyze a generalization of such metamaterials where a simple aperture is now replaced by a compound object formed by superposition of two or more primitive objects (e.g., rectangles, circles, and ellipses). Thus obtained “super unit cell” shows far richer behavior than the subobjects that comprise it. We show that nonlocalities introduced by overlapping simple subobjects can be used to produce large deviations of spectral dispersion even for small additive modifications of the basic geometry. Technologically, some super cells may be fabricated by simple spatial shifting of the existing photolithographic masks. In our investigation we applied analytical calculations andab initiofinite element modeling to prove the possibility to tailor the dispersion including resonances for plasmonic nanocomposites by adjusting the local geometry and exploiting localized interactions at a subwavelength level. Any desired form could be defined using simple primitive objects, making the situation a geometrical analog of the case of series expansion of a function. Thus an additional degree of tunability of metamaterials is obtained. The obtained designer structures can be applied in different fields like waveguiding and sensing.


2005 ◽  
Vol 45 (4) ◽  
pp. 294-295 ◽  
Author(s):  
Aaron D. Scher ◽  
Christopher T. Rodenbeck ◽  
Kai Chang

2013 ◽  
Vol 30 (4) ◽  
pp. 1077 ◽  
Author(s):  
Alexander O. Korotkevich ◽  
Kathryn E. Rasmussen ◽  
Gregor Kovačič ◽  
Victor Roytburd ◽  
Andrei I. Maimistov ◽  
...  

2016 ◽  
Vol 30 (07) ◽  
pp. 1650088
Author(s):  
Valeriy M. Ishchuk ◽  
Vladimir Sobolev

In this paper, a possibility of use of the controlled decomposition of solid solutions of oxides with perovskite structure in the state of coexisting domains of the antiferroelectric (AFE) and ferroelectric (FE) phases for manufacturing materials with the negative refractive index is demonstrated. The lead zirconate titanate-based solid solutions are considered as an example of substances suitable for creation of such materials. Manufactured composites constitute a dielectric AFE matrix with a structure of conducting interphase boundaries separating domains of the FE and AFE phases. The electric conductivity of the interphase boundaries occurs as a result of the local decomposition of the solid solutions in the vicinity of these boundaries. The decomposition process and consequently the conductivity of the interphase boundaries can be controlled by means of external influences.


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