The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Michael I Mishchenko - One of the best experts on this subject based on the ideXlab platform.

  • impressed sources and fields in the volume integral equation formulation of Electromagnetic Scattering by a finite object a tutorial
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2018
    Co-Authors: Michael I Mishchenko, Maxim A Yurkin
    Abstract:

    Abstract Although free space cannot generate Electromagnetic waves, the majority of existing accounts of frequency-domain Electromagnetic Scattering by particles and particle groups are based on the postulate of existence of an impressed incident field, usually in the form of a plane wave. In this tutorial we discuss how to account for the actual existence of impressed source currents rather than impressed incident fields. Specifically, we outline a self-consistent theoretical formalism describing Electromagnetic Scattering by an arbitrary finite object in the presence of arbitrarily distributed impressed currents, some of which can be far removed from the object and some can reside in its vicinity, including inside the object. To make the resulting formalism applicable to a wide range of Scattering-object morphologies, we use the framework of the volume integral equation formulation of Electromagnetic Scattering, couple it with the notion of the transition operator, and exploit the fundamental symmetry property of this operator. Among novel results, this tutorial includes a streamlined proof of fundamental symmetry (reciprocity) relations, a simplified derivation of the Foldy equations, and an explicit analytical expression for the transition operator of a multi-component Scattering object.

  • first principles modeling of Electromagnetic Scattering by discrete and discretely heterogeneous random media
    arXiv: Optics, 2016
    Co-Authors: Michael I Mishchenko, Janna M Dlugach, Maxim A Yurkin, Brian Cairns, Li Liu, Lee R Panetta, Larry D Travis, Ping Yang, Nadezhda T Zakharova
    Abstract:

    The main objective of this Report is to formulate the general theoretical framework of Electromagnetic Scattering by discrete random media rooted in the Maxwell-Lorentz Electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell-Lorentz equations, we trace the development of the first-principles formalism enabling accurate calculations of monochromatic and quasi-monochromatic Scattering by static and randomly varying multiparticle groups. We illustrate how this general framework can be coupled with state-of-the-art computer solvers of the Maxwell equations and applied to direct modeling of Electromagnetic Scattering by representative random multi-particle groups with arbitrary packing densities. This first-principles modeling yields general physical insights unavailable with phenomenological approaches. We discuss how the first-order-Scattering approximation, the radiative transfer theory, and the theory of weak localization of Electromagnetic waves can be derived as immediate corollaries of the Maxwell equations for very specific and well-defined kinds of particulate medium. These recent developments confirm the mesoscopic origin of the radiative transfer, weak localization, and effective-medium regimes and help evaluate the numerical accuracy of widely used approximate modeling methodologies.

  • first principles modeling of Electromagnetic Scattering by discrete and discretely heterogeneous random media
    Physics Reports, 2016
    Co-Authors: Michael I Mishchenko, Janna M Dlugach, Maxim A Yurkin, Brian Cairns, Li Liu, Lee R Panetta, Larry D Travis, Ping Yang, Nadezhda T Zakharova
    Abstract:

    A discrete random medium is an object in the form of a finite volume of a vacuum or a homogeneous material medium filled with quasi-randomly and quasi-uniformly distributed discrete macroscopic impurities called small particles. Such objects are ubiquitous in natural and artificial environments. They are often characterized by analyzing theoretically the results of laboratory, in situ, or remote-sensing measurements of the Scattering of light and other Electromagnetic radiation. Electromagnetic Scattering and absorption by particles can also affect the energy budget of a discrete random medium and hence various ambient physical and chemical processes. In either case Electromagnetic Scattering must be modeled in terms of appropriate optical observables, i.e., quadratic or bilinear forms in the field that quantify the reading of a relevant optical instrument or the Electromagnetic energy budget. It is generally believed that time-harmonic Maxwell's equations can accurately describe elastic Electromagnetic Scattering by macroscopic particulate media that change in time much more slowly than the incident Electromagnetic field. However, direct solutions of these equations for discrete random media had been impracticable until quite recently. This has led to a widespread use of various phenomenological approaches in situations when their very applicability can be questioned. Recently, however, a new branch of physical optics has emerged wherein Electromagnetic Scattering by discrete and discretely heterogeneous random media is modeled directly by using analytical or numerically exact computer solutions of the Maxwell equations. Therefore, the main objective of this Report is to formulate the general theoretical framework of Electromagnetic Scattering by discrete random media rooted in the Maxwell-Lorentz Electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell-Lorentz equations, we trace the development of the first-principles formalism enabling accurate calculations of monochromatic and quasi-monochromatic Scattering by static and randomly varying multiparticle groups. We illustrate how this general framework can be coupled with state-of-the-art computer solvers of the Maxwell equations and applied to direct modeling of Electromagnetic Scattering by representative random multi-particle groups with arbitrary packing densities. This first-principles modeling yields general physical insights unavailable with phenomenological approaches. We discuss how the first-order-Scattering approximation, the radiative transfer theory, and the theory of weak localization of Electromagnetic waves can be derived as immediate corollaries of the Maxwell equations for very specific and well-defined kinds of particulate medium. These recent developments confirm the mesoscopic origin of the radiative transfer, weak localization, and effective-medium regimes and help evaluate the numerical accuracy of widely used approximate modeling methodologies.

  • Electromagnetic Scattering by particles and particle groups an introduction
    2014
    Co-Authors: Michael I Mishchenko
    Abstract:

    Preface Acknowledgements 1. Introduction 2. The macroscopic Maxwell equations and monochromatic fields 3. Fundamental homogeneous-medium solutions of the macroscopic Maxwell equations 4. Basic theory of frequency-domain Electromagnetic Scattering by a fixed finite object 5. Far-field Scattering 6. The Foldy equations 7. The Stokes parameters 8. Poynting-Stokes tensor 9. Polychromatic Electromagnetic fields 10. Polychromatic Scattering by fixed and randomly changing objects 11. Measurement of Electromagnetic energy flow 12. Measurement of the Stokes parameters 13. Description of far-field Scattering in terms of actual optical observables 14. Electromagnetic Scattering by a small random group of sparsely distributed particles 15. Statistically isotropic and mirror-symmetric random particles 16. Numerical computations and laboratory measurements of Electromagnetic Scattering 17. Far-field observables: qualitative and quantitative traits 18. Electromagnetic Scattering by discrete random media: far field 19. Near-field Scattering by a sparse discrete random medium: microphysical radiative transfer theory 20. Radiative transfer in plane-parallel particulate media 21. Weak localization 22. Epilogue Appendix A. Dyads and dyadics Appendix B. Free-space dyadic Green's function Appendix C. Euler rotation angles Appendix D. Spherical-wave expansion of a plane wave in the far zone Appendix E. Integration quadrature formulas Appendix F. Wigner d-functions Appendix G. Stationary phase evolution of a double integral Appendix H. Hints and answers to selected problems Appendix I. List of acronyms References Index.

  • gustav mie and the fundamental concept of Electromagnetic Scattering by particles a perspective
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2009
    Co-Authors: Michael I Mishchenko
    Abstract:

    This tutorial review provides a general discussion of the fundamental concept of Electromagnetic Scattering by particles and particle groups and dispels certain widespread yet profoundly confusing misconceptions.

Maxim A Yurkin - One of the best experts on this subject based on the ideXlab platform.

  • impressed sources and fields in the volume integral equation formulation of Electromagnetic Scattering by a finite object a tutorial
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2018
    Co-Authors: Michael I Mishchenko, Maxim A Yurkin
    Abstract:

    Abstract Although free space cannot generate Electromagnetic waves, the majority of existing accounts of frequency-domain Electromagnetic Scattering by particles and particle groups are based on the postulate of existence of an impressed incident field, usually in the form of a plane wave. In this tutorial we discuss how to account for the actual existence of impressed source currents rather than impressed incident fields. Specifically, we outline a self-consistent theoretical formalism describing Electromagnetic Scattering by an arbitrary finite object in the presence of arbitrarily distributed impressed currents, some of which can be far removed from the object and some can reside in its vicinity, including inside the object. To make the resulting formalism applicable to a wide range of Scattering-object morphologies, we use the framework of the volume integral equation formulation of Electromagnetic Scattering, couple it with the notion of the transition operator, and exploit the fundamental symmetry property of this operator. Among novel results, this tutorial includes a streamlined proof of fundamental symmetry (reciprocity) relations, a simplified derivation of the Foldy equations, and an explicit analytical expression for the transition operator of a multi-component Scattering object.

  • first principles modeling of Electromagnetic Scattering by discrete and discretely heterogeneous random media
    arXiv: Optics, 2016
    Co-Authors: Michael I Mishchenko, Janna M Dlugach, Maxim A Yurkin, Brian Cairns, Li Liu, Lee R Panetta, Larry D Travis, Ping Yang, Nadezhda T Zakharova
    Abstract:

    The main objective of this Report is to formulate the general theoretical framework of Electromagnetic Scattering by discrete random media rooted in the Maxwell-Lorentz Electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell-Lorentz equations, we trace the development of the first-principles formalism enabling accurate calculations of monochromatic and quasi-monochromatic Scattering by static and randomly varying multiparticle groups. We illustrate how this general framework can be coupled with state-of-the-art computer solvers of the Maxwell equations and applied to direct modeling of Electromagnetic Scattering by representative random multi-particle groups with arbitrary packing densities. This first-principles modeling yields general physical insights unavailable with phenomenological approaches. We discuss how the first-order-Scattering approximation, the radiative transfer theory, and the theory of weak localization of Electromagnetic waves can be derived as immediate corollaries of the Maxwell equations for very specific and well-defined kinds of particulate medium. These recent developments confirm the mesoscopic origin of the radiative transfer, weak localization, and effective-medium regimes and help evaluate the numerical accuracy of widely used approximate modeling methodologies.

  • first principles modeling of Electromagnetic Scattering by discrete and discretely heterogeneous random media
    Physics Reports, 2016
    Co-Authors: Michael I Mishchenko, Janna M Dlugach, Maxim A Yurkin, Brian Cairns, Li Liu, Lee R Panetta, Larry D Travis, Ping Yang, Nadezhda T Zakharova
    Abstract:

    A discrete random medium is an object in the form of a finite volume of a vacuum or a homogeneous material medium filled with quasi-randomly and quasi-uniformly distributed discrete macroscopic impurities called small particles. Such objects are ubiquitous in natural and artificial environments. They are often characterized by analyzing theoretically the results of laboratory, in situ, or remote-sensing measurements of the Scattering of light and other Electromagnetic radiation. Electromagnetic Scattering and absorption by particles can also affect the energy budget of a discrete random medium and hence various ambient physical and chemical processes. In either case Electromagnetic Scattering must be modeled in terms of appropriate optical observables, i.e., quadratic or bilinear forms in the field that quantify the reading of a relevant optical instrument or the Electromagnetic energy budget. It is generally believed that time-harmonic Maxwell's equations can accurately describe elastic Electromagnetic Scattering by macroscopic particulate media that change in time much more slowly than the incident Electromagnetic field. However, direct solutions of these equations for discrete random media had been impracticable until quite recently. This has led to a widespread use of various phenomenological approaches in situations when their very applicability can be questioned. Recently, however, a new branch of physical optics has emerged wherein Electromagnetic Scattering by discrete and discretely heterogeneous random media is modeled directly by using analytical or numerically exact computer solutions of the Maxwell equations. Therefore, the main objective of this Report is to formulate the general theoretical framework of Electromagnetic Scattering by discrete random media rooted in the Maxwell-Lorentz Electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell-Lorentz equations, we trace the development of the first-principles formalism enabling accurate calculations of monochromatic and quasi-monochromatic Scattering by static and randomly varying multiparticle groups. We illustrate how this general framework can be coupled with state-of-the-art computer solvers of the Maxwell equations and applied to direct modeling of Electromagnetic Scattering by representative random multi-particle groups with arbitrary packing densities. This first-principles modeling yields general physical insights unavailable with phenomenological approaches. We discuss how the first-order-Scattering approximation, the radiative transfer theory, and the theory of weak localization of Electromagnetic waves can be derived as immediate corollaries of the Maxwell equations for very specific and well-defined kinds of particulate medium. These recent developments confirm the mesoscopic origin of the radiative transfer, weak localization, and effective-medium regimes and help evaluate the numerical accuracy of widely used approximate modeling methodologies.

Lei Shi - One of the best experts on this subject based on the ideXlab platform.

  • Electromagnetic Scattering laws in weyl systems
    Nature Communications, 2017
    Co-Authors: Ming Zhou, Lei Ying, Lei Shi
    Abstract:

    Wavelength determines the length scale of the cross section when Electromagnetic waves are scattered by an electrically small object. The cross section diverges for resonant Scattering, and diminishes for non-resonant Scattering, when wavelength approaches infinity. This Scattering law explains the colour of the sky as well as the strength of a mobile phone signal. We show that such wavelength scaling comes from the conical dispersion of free space at zero frequency. Emerging Weyl systems, offering similar dispersion at non-zero frequencies, lead to new laws of Electromagnetic Scattering that allow cross sections to be decoupled from the wavelength limit. Diverging and diminishing cross sections can be realized at any target wavelength in a Weyl system, providing the ability to tailor the strength of wave–matter interactions for radiofrequency and optical applications. Scattering characteristics are important optical properties but they depend strongly on the relative Electromagnetic size and environment of a particle. Here, the authors study the frequency-dependence of the Scattering cross section for a scatterer located inside a photonic Weyl system.

  • Electromagnetic Scattering laws in weyl systems
    arXiv: Optics, 2017
    Co-Authors: Ming Zhou, Lei Ying, Lei Shi
    Abstract:

    Wavelength determines the length scale of the cross section when Electromagnetic waves are scattered by an electrically small object. The cross section diverges for resonant Scattering, and diminishes for non-resonant Scattering, when wavelength approaches infinity. This Scattering law explains the color of the sky as well as the strength of a mobile phone signal. We show that such wavelength scaling comes from free space's conical dispersion at zero frequency. Emerging Weyl systems, offering similar dispersion at non-zero frequencies, lead to new laws of Electromagnetic Scattering that allow cross sections to be decoupled from the wavelength limit. Diverging and diminishing cross sections can be realized at any target wavelength in a Weyl system, providing unprecedented ability to tailor the strength of wave-matter interactions for radio-frequency and optical applications.

Felipe Vico - One of the best experts on this subject based on the ideXlab platform.

Zydrunas Gimbutas - One of the best experts on this subject based on the ideXlab platform.

  • the decoupled potential integral equation for time harmonic Electromagnetic Scattering
    Communications on Pure and Applied Mathematics, 2016
    Co-Authors: Felipe Vico, Leslie Greengard, Miguel Ferrando, Zydrunas Gimbutas
    Abstract:

    This is the peer reviewed version of the following article: "Vico, F., Ferrando, M., Greengard, L. and Gimbutas, Z. (2016), The Decoupled Potential Integral Equation for Time-Harmonic Electromagnetic Scattering. Commun. Pur. Appl. Math., 69: 771–812", which has been published in final form at http://dx.doi.org/10.1002/cpa.21585. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

  • the decoupled potential integral equation for time harmonic Electromagnetic Scattering
    Communications on Pure and Applied Mathematics, 2016
    Co-Authors: Felipe Vico, Leslie Greengard, Miguel Ferrando, Zydrunas Gimbutas
    Abstract:

    This is the peer reviewed version of the following article: "Vico, F., Ferrando, M., Greengard, L. and Gimbutas, Z. (2016), The Decoupled Potential Integral Equation for Time-Harmonic Electromagnetic Scattering. Commun. Pur. Appl. Math., 69: 771–812", which has been published in final form at http://dx.doi.org/10.1002/cpa.21585. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.