Eigenmodes of Light Propagating in Cholesteric Liquid Crystal

Cholesteric liquid crystals (CLCs) are widely used in optical applications, because they spontaneously organize in a periodic structure leading to a photonic band gap with high reflectivity. Usually the reflection in the perpendicular direction is exploited, but for many applications a deeper understanding of the optical behavior of this material would be very useful. In this study, we employ the Floquet theorem to analyze the optical properties of bulk modes in CLC and the electric field. This approach allows us to explore the band gap as a function of the wave vector and polarization of propagating modes inside the CLC and how they are outcoupled into the external medium.