TY - JOUR

T1 - New perspective on the reciprocity theorem of classical electrodynamics

AU - Mansuripur, Masud

AU - Tsai, Din Ping

N1 - Funding Information:
The authors are grateful to Pui-Tak Leung for many helpful discussions. We also thank the anonymous referee who drew our attention to Refs. [19–21] . One of the authors (M.M.) also would like to acknowledge the support from the National Science Council of Taiwan while he was on sabbatical leave at the National Taiwan University in Taipei.

PY - 2011/2/1

Y1 - 2011/2/1

N2 - We provide a simple physical proof of the reciprocity theorem of classical electrodynamics in the general case of material media that contain linearly polarizable as well as linearly magnetizable substances. The excitation source is taken to be a point-dipole, either electric or magnetic, and the monitored field at the observation point can be electric or magnetic, regardless of the nature of the source dipole. The electric and magnetic susceptibility tensors of the material system may vary from point to point in space, but they cannot be functions of time. In the case of spatially non-dispersive media, the only other constraint on the local susceptibility tensors is that they be symmetric at each and every point. The proof is readily extended to media that exhibit spatial dispersion: For reciprocity to hold, the electric susceptibility tensor χE-mn that relates the complex-valued magnitude of the electric dipole at location rm to the strength of the electric field at r n must be the transpose of χE-nm. Similarly, the necessary and sufficient condition for the magnetic susceptibility tensor is χM-mn = χTM-nm.

AB - We provide a simple physical proof of the reciprocity theorem of classical electrodynamics in the general case of material media that contain linearly polarizable as well as linearly magnetizable substances. The excitation source is taken to be a point-dipole, either electric or magnetic, and the monitored field at the observation point can be electric or magnetic, regardless of the nature of the source dipole. The electric and magnetic susceptibility tensors of the material system may vary from point to point in space, but they cannot be functions of time. In the case of spatially non-dispersive media, the only other constraint on the local susceptibility tensors is that they be symmetric at each and every point. The proof is readily extended to media that exhibit spatial dispersion: For reciprocity to hold, the electric susceptibility tensor χE-mn that relates the complex-valued magnitude of the electric dipole at location rm to the strength of the electric field at r n must be the transpose of χE-nm. Similarly, the necessary and sufficient condition for the magnetic susceptibility tensor is χM-mn = χTM-nm.

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U2 - 10.1016/j.optcom.2010.09.077

DO - 10.1016/j.optcom.2010.09.077

M3 - Article

AN - SCOPUS:78649991080

SN - 0030-4018

VL - 284

SP - 707

EP - 714

JO - Optics Communications

JF - Optics Communications

IS - 3

ER -