Polarization transformation characteristics of a statified slab consisting of uniaxial chiral layers are investigated. It is assumed that a plane electromagnetic wave with arbitrary polarization is normally incident from free space on the stratified slab, which is located on a dielectric substrate. Note that the electric field inside a uniaxial chiral layer is expressed as a sum of four plane waves with different wavenumbers. The wavenumbers are found by seeking non-trivial solutions of the constitutive relations with Maxwell's equations. The electric field components of the transmitted and reflected waves can be obtained from a chainmatrix formalism. The powers and the Stokes parameters of the two waves are represented in terms of their electric field components. As is well known, the Stokes parameters uniquely describe every possible state of polarization of a plane wave. Numerical results are presented for two types of uniaxial chiral structure. The cross- and co-polarized powers and the Stokes parameters of the transmitted and reflected waves are computed for the incident plane wave of linear polarization. The results demonstrate a significant polarization transformation of the transmitted wave. Then it is shown that the stratified slab can be used as efficient polarization-transformation transmission filters active at some frequency band.

Scattering characteristics of a stratified chiral slab, which is composed of dielectric chiral layers of different material properties and thicknesses, are extensively explored. Design considerations for optical filters are also presented for both the cases of normal and oblique incidence. In the analysis, the incident field is assumed to be a plane monochromatic wave of any arbitrary polarization. The transmitted and reflected electric fields are obtained by noting the fact that the electric field inside a chiral medium is expressed as a sum of the left- and right-circularly polarized plane waves of different phase velocities. Then one can describe the power densities and the Stokes parameters of the transmitted and reflected waves in terms of their field components. As is well known,the Stokes parameters characterize every possible state of polarization of a plane wave. Numerical examples are presented to show the effects of chirality on polarization conversion properties of the stratified chiral slab. The cross- and co-polarized powers and the Stokes parameters of the transmitted and reflected waves are computed for the incident wave of perpendicular polarization. The numerical results demonstrate novel depolarization properties of the slab with application to the design of efficient filters active at the optical region. It is seen from the results that the stratified chiral slab acts as a polarization-conversion transmission filter that passes only a cross-polarized component of the transmitted wave at some frequency band. Furthermore, the slab may be utilized as an antireflection filter for both the cross- and co-po1arized components of the reflected wave at the band region.