TY - JOUR

T1 - Impressed sources and fields in the volume-integral-equation formulation of electromagnetic scattering by a finite object: A tutorial

AU - Mishchenko, Michael I.

AU - Yurkin, Maxim A.

PY - 2018/7/1

Y1 - 2018/7/1

N2 - 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.

AB - 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.

KW - Electromagnetic scattering

KW - Impressed fields

KW - Impressed sources

KW - Symmetry relations

KW - Transition dyadic

KW - Volume integral equation

KW - RADIATIVE HEAT-TRANSFER

KW - DISCRETE-DIPOLE APPROXIMATION

KW - T-MATRIX

KW - DOMAIN

KW - ELECTRODYNAMICS

KW - LIGHT-SCATTERING

KW - MULTIPLE-SCATTERING

KW - WAVES

UR - http://www.scopus.com/inward/record.url?scp=85046794524&partnerID=8YFLogxK

U2 - 10.1016/j.jqsrt.2018.04.023

DO - 10.1016/j.jqsrt.2018.04.023

M3 - Article

C2 - 30082926

AN - SCOPUS:85046794524

VL - 214

SP - 158

EP - 167

JO - Journal of Quantitative Spectroscopy and Radiative Transfer

JF - Journal of Quantitative Spectroscopy and Radiative Transfer

SN - 0022-4073

ER -