scholarly journals Effect of shape in near-field thermal transfer for periodic structures

2015 ◽  
Vol 91 (17) ◽  
Author(s):  
Hamidreza Chalabi ◽  
Erez Hasman ◽  
Mark L. Brongersma
Keyword(s):  
Periodic Structures ◽  
Near Field ◽  
Thermal Transfer

scholarly journals Imaging of bi-anisotropic periodic structures from electromagnetic near-field data

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dinh-Liem Nguyen ◽  
Trung Truong
Keyword(s):  
Inverse Scattering ◽  
Maxwell Equations ◽  
Field Data ◽  
Periodic Structures ◽  
Near Field ◽  
Scattering Problem ◽  
Three Dimensional ◽  
Inverse Scattering Problem ◽  
Factorization Method ◽  
Unique Determination

AbstractThis paper is concerned with the inverse scattering problem for the three-dimensional Maxwell equations in bi-anisotropic periodic structures. The inverse scattering problem aims to determine the shape of bi-anisotropic periodic scatterers from electromagnetic near-field data at a fixed frequency. The factorization method is studied as an analytical and numerical tool for solving the inverse problem. We provide a rigorous justification of the factorization method which results in the unique determination and a fast imaging algorithm for the periodic scatterer. Numerical examples for imaging three-dimensional periodic structures are presented to examine the efficiency of the method.

scholarly journals Nanoscale Thermal Transfer – An Invitation to Fluctuation Electrodynamics

2017 ◽  
Vol 72 (2) ◽  
pp. 99-108 ◽  
Author(s):  
Carsten Henkel
Keyword(s):  
Heat Transfer ◽  
Thermal Radiation ◽  
Near Field ◽  
Electromagnetic Theory ◽  
Physical Content ◽  
Thermal Transfer ◽  
The Status ◽  
Basic Concepts

AbstractAn electromagnetic theory of thermal radiation is outlined, based on the fluctuation electrodynamics of Rytov and co-workers. We discuss the basic concepts and the status of different approximations. The physical content is illustrated with a few examples on near-field heat transfer.

scholarly journals An ab-initio coupled mode theory for near field radiative thermal transfer

2014 ◽  
Vol 22 (24) ◽  
pp. 30032 ◽  
Author(s):  
Hamidreza Chalabi ◽  
Erez Hasman ◽  
Mark L. Brongersma
Keyword(s):  
Ab Initio ◽  
Near Field ◽  
Coupled Mode Theory ◽  
Mode Theory ◽  
Coupled Mode ◽  
Thermal Transfer

scholarly journals Periodic structures on liquid-phase smectic A, nematic and isotropic free surfaces

2018 ◽  
Vol 9 ◽  
pp. 342-352
Author(s):  
Anna N Bagdinova ◽  
Evgeny I Demikhov ◽  
Nataliya G Borisenko ◽  
Sergei M Tolokonnikov ◽  
Gennadii V Mishakov ◽  
...  
Keyword(s):  
Periodic Structures ◽  
Near Field ◽  
Optical Microscope ◽  
Isotropic Liquid ◽  
Free Surfaces ◽  
Smectic A ◽  
Atomic Force ◽  
Liquid Phases ◽  
Stripe Structure ◽  
Structure Analyzer

The free boundary of smectic A (SmA), nematic and isotropic liquid phases were studied using a polarized optical microscope, an interferometric surface structure analyzer (ISSA), an atomic force microscope (AFM) and a scanning near-field optical microscope (SNOM). Images of the SmA phase free surface obtained by the polarized microscope and ISSA are in good correlation and show a well-known focal domain structure. The new periodic stripe structure was observed by scanning near-field optical microscopy on the surface of the smectic A, nematic and isotropic phases. The properties of this periodic structure are similar to the charged liquid helium surface and can be explained by nonlinear electrostatic instabilities previously described.

scholarly journals Spatially variant periodic structures in electromagnetics

2015 ◽  
Vol 373 (2049) ◽  
pp. 20140359 ◽  
Author(s):  
Raymond C. Rumpf ◽  
Javier J. Pazos ◽  
Jennefir L. Digaum ◽  
Stephen M. Kuebler
Keyword(s):  
Photonic Crystals ◽  
Electromagnetic Compatibility ◽  
Extreme Values ◽  
Periodic Structures ◽  
Numerical Technique ◽  
Near Field ◽  
Functionally Graded ◽  
Electromagnetic Properties ◽  
Spatially Variant ◽  
Constitutive Parameters

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.

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