Effective properties of a periodic chiral arrangement of identical biaxially dielectric plates

A periodically inhomogeneous medium is constructed by stacking up unit cells made of (identical) structurally chiral slabs. Each structurally chiral slab is comprised of a certain number of identical biaxially anisotropic plates, the consecutive optic axes describing either a right-or a left-handed spiral. The characteristic matrix of the unit cell is obtained and used with the Floquet-Lyapunov theorem to obtain the electromagnetic fields in the periodic medium. When the unit cell thickness is very small compared to the principal wavelengths in the biaxial plates, the periodically inhomogeneous biaxial medium is shown to be equivalent to a homogeneous biaxial medium, the two optic axes of the equivalent medium being dependent on the handedness of the periodic medium.