Reflection of obliquely incident plane wave from chiral slab backed by soft and hard surface

The general case of a plane wave reflection from a chiral slab backed by a soft and hard surface is considered. Fields in the chiral slab are represented in right-hand and left-hand circularly polarised basis. The same basis is used to derive the reflection dyadic. Expanding fields in circularly polarised vectors are advantageous, because circularly polarised waves are the eigenwaves of the chiral medium; moreover they are not coupled by the boundary condition of the soft and hard surface. However, there is some coupling at the interface of the chiral medium and free space, which complicates the analysis.