Near-field analysis of electromagnetic chirality in the Mie scattering by a dielectric sphere

Abstract

We revisit the Mie scattering in view of electromagnetic chirality, especially in the near field of a scattering sphere. To this goal, we take the simplest two-dielectric system where both an embedding medium and an embedded sphere are loss-free, non-magnetic, and dielectric. For a given linearly polarized incident wave, the net chirality should vanish when integrated over the whole space. The reactive chirality indicating the divergence-full spin angular momentum density shows an analogous behavior. Meanwhile, the electromagnetic chirality obtained in response to a circularly polarized incident wave exhibits distinct super-chiral behaviors. In addition, we examined key bilinear parameters for another incident wave, where two orthogonal linearly polarized waves are combined without a phase delay.