Title
Minimum principles in electromagnetic scattering by small aspherical particles
Document Type
Article
Publication Date
8-14-2013
Abstract
We consider the question of optimal shapes, e.g., those causing minimal extinction among all shapes of equal volume. Guided by the isoperimetric property of a sphere, relevant in the geometrical optics limit of scattering by large particles, we examine an analogous question in the low frequency approximation, seeking to disentangle electric and geometric contributions. To that end, we survey the literature on shape functionals and focus on ellipsoids, giving a simple discussion of spherical optimality for the coated ellipsoidal particle. Monotonic increase with asphericity in the low frequency regime for orientation-averaged induced dipole moments and scattering cross-sections is also shown. Additional physical insight is obtained from the Rayleigh–Gans (transparent) limit and eccentricity expansions. We propose connecting low and high frequency regimes in a single minimum principle valid for all size parameters, provided that reasonable size distributions of randomly oriented aspherical particles wash out the resonances for intermediate size parameters. This proposal is further supported by the sum rule for integrated extinction.
Publication Title
Journal of Quantitative Spectroscopy and Radiative Transfer
Recommended Citation
Kostinski, A.,
&
Mongkolsittisilp, A.
(2013).
Minimum principles in electromagnetic scattering by small aspherical particles.
Journal of Quantitative Spectroscopy and Radiative Transfer,
131, 194-201.
http://doi.org/10.1016/j.jqsrt.2013.08.006
Retrieved from: https://digitalcommons.mtu.edu/physics-fp/183
Publisher's Statement
Copyright © 2013 Elsevier Ltd. Published by Elsevier B.V. All rights reserved. Publisher's version of record: https://doi.org/10.1016/j.jqsrt.2013.08.006