Spatially variant periodic structures in electromagnetics.

Autor:	Rumpf RC; EM Lab, W. M. Keck Center for 3D Innovation, University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968, USA rcrumpf@utep.edu., Pazos JJ; EM Lab, W. M. Keck Center for 3D Innovation, University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968, USA., Digaum JL; CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USA., Kuebler SM; CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USA Chemistry Department, University of Central Florida, Orlando, FL 32816, USA Physics Department, University of Central Florida, Orlando, FL 32816, USA.
Jazyk:	angličtina
Zdroj:	Philosophical transactions. Series A, Mathematical, physical, and engineering sciences [Philos Trans A Math Phys Eng Sci] 2015 Aug 28; Vol. 373 (2049).
DOI:	10.1098/rsta.2014.0359
Abstrakt:	Spatial transforms are a popular technique for designing periodic structures that are macroscopically inhomogeneous. The structures are often required to be anisotropic, provide a magnetic response, and to have extreme values for the constitutive parameters in Maxwell's equations. Metamaterials and photonic crystals are capable of providing these, although sometimes only approximately. The problem still remains about how to generate the geometry of the final lattice when it is functionally graded, or spatially varied. This paper describes a simple numerical technique to spatially vary any periodic structure while minimizing deformations to the unit cells that would weaken or destroy the electromagnetic properties. New developments in this algorithm are disclosed that increase efficiency, improve the quality of the lattices and provide the ability to design aplanatic metasurfaces. The ability to spatially vary a lattice in this manner enables new design paradigms that are not possible using spatial transforms, three of which are discussed here. First, spatially variant self-collimating photonic crystals are shown to flow unguided waves around very tight bends using ordinary materials with low refractive index. Second, multi-mode waveguides in spatially variant band gap materials are shown to guide waves around bends without mixing power between the modes. Third, spatially variant anisotropic materials are shown to sculpt the near-field around electric components. This can be used to improve electromagnetic compatibility between components in close proximity. (© 2015 The Author(s) Published by the Royal Society. All rights reserved.)
Databáze:	MEDLINE
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