Influence of chiral shapes of individual inclusions on the absorption in chiral composite coatings

This paper presents a theoretical investigation of reflection properties of planar layers of chiral composite materials. The goal of the study is to clarify the influence of inclusion shape on reflection and absorption in chiral mixtures. It is explained why the slabs of low-density isotropic chiral and racemic mixtures of chiral particles of conventional shapes (helices, wire-and-loop elements) possess very similar reflective properties for waves coming from the normal direction. In particular, we consider certain ''asymmetric'' chiral shapes, such that the chirality factor of single individual particles modifies the effective permittivity and permeability of mixtures with many inclusions. Numerical examples demonstrate typical properties of lossy chiral slabs.