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DOI: 10.5445/IR/1000076706

Broadband suppression of backscattering at optical frequencies using low permittivity dielectric spheres

Ismail Abdelrahman, M.; Rockstuhl, Carsten; Fernandez-Corbaton, Ivan

The exact suppression of backscattering from rotationally symmetric objects requires dual symmetric materials where εr = μr. This prevents their design at many frequency bands, including the optical one, because magnetic materials are not available. Electromagnetically small non-magnetic spheres of large permittivity offer an alternative. They can be tailored to exhibit balanced electric and magnetic dipole polarizabilities a1 = b1, which result in approximate zero backscattering. In this case, the effect is inherently narrowband. Here, we put forward a different alternative that allows broadband functionality: Wavelength-sized spheres made from low permittivity materials. The effect occurs in a parameter regime where approximate duality is met for all multipolar order a n  ≈ b n , in a weakly wavelength dependence fashion. In addition, and despite of the low permittivity, the overall scattering response of these spheres is still significant. Scattering patterns are shown to be highly directive across an octave spanning band. The effect is analytically and numerically shown using the Mie coefficients.

Zugehörige Institution(en) am KIT Institut für Nanotechnologie (INT)
Institut für Theoretische Festkörperphysik (TFP)
Publikationstyp Zeitschriftenaufsatz
Jahr 2017
Sprache Englisch
Identifikator ISSN: 2045-2322
URN: urn:nbn:de:swb:90-767068
KITopen ID: 1000076706
HGF-Programm 43.23.01; LK 01
Erschienen in Scientific reports
Band 7
Heft 1
Seiten Art.Nr. 14762
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
Schlagworte Nanoparticles; Nanophotonics and plasmonics
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