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

Abstract

The exact suppression of backscattering from rotationally symmetric objects requires dual symmetric materials where ${\epsilon }_r={\mu }_r$. 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, 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: Electromagnetically large spheres made from low permittivity materials. The effect occurs in a parameter regime that approaches the trivial ${\epsilon }_r\to {\mu }_r=1$ case, where approximate duality is met in a weakly wavelength dependence fashion. Despite the low permittivity, the overall scattering response of the spheres is still significant. Radiation patterns from these spheres are shown to be highly directive across an octave spanning band. The effect is analytically and numerically shown using the Mie coefficients.

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References in corpus (11)

• High-efficiency light-wave control with all-dielectric optical Huygens' metasurfaces
• Directional visible light scattering by silicon nanoparticles
• Magnetic light
• Backward Pulling Force from a Forward Propagating Beam
• Strong magnetic response of submicron Silicon particles in the infrared
• Demonstration of zero optical backscattering from single nanoparticles
• Electromagnetic duality symmetry and helicity conservation for the macroscopic Maxwell's equations (previously "Experimental demonstration of electromagnetic duality symmetry breaking")
• Forward and backward helicity scattering coefficients for systems with discrete rotational symmetry
• Dual and anti-dual modes in dielectric spheres
• Dual and chiral objects for optical activity in general scattering directions
• Dielectric spheres with maximum forward scattering and zero backscattering: A search for their material composition

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• Insights into broadband backscattering suppression in solar cells from the helicity preservation point of view