Electromagnetic chirality of an isotropic, chiral and spherical scatterer

Chiral media enable the control and manipulation of the dierent polarization states of light. Maximally em-chiral objects, which are transparent to light of one helicity but not to the other, can be used as non-directional polarizers or in the detection of chiral molecules. Scattering by chiral spheres is well researched in literature. However, most of these works are theoretical and focus on the general scattering behavior. Therein, very large chirality parameters are assumed, for which media are hard to fabricate in the optical regime. In this work we search for intrinsically chiral, isotropic, homogeneous spherical particles, which are maximally em-chiral.We investigate the inuence of geometry and material parameters on this quantity.After discussing the theory to describe the scattering by a chiral spherical particle and restricting the parameter space by means of a microscopic model for the chiral scatterers, single chiral spheres and core-shell particles
are investigated by means of parameter studies. The chirality of the medium is found to restrict the overall em-chirality of the scatterer, such that for weakly chiral spheres and core-shell particles highly em-chiral congurations are exceptional cases. ... mehrThese exceptions are found in regions where the media meet the refractive index matching condition with the surrounding medium and thus show high em-chirality. High em-chirality is also found for weakly chiral spheres with a thin dielectric coating for specic media and geometries of the core-shell.
These objects are appealing for a larger number of applications and
seem to be in reach experimentally.