Light wave propagation in periodic tilted liquid crystal structures: a periodic beam propagation method

Periodically deformed liquid crystal profiles are commonly encountered either spontaneously under the influence of an external excitation, or intentionally, with the introduction of relief type gratings on the supporting surfaces. These types of periodicity are often characterized by a pitch around one micron or less. As the pitch is directly comparable to the optical wavelength, it is necessary to develop rigorous numerical methods to predict light wave propagation within such structures. A wide angle periodic beam propagation method (BPM) is proposed for the simulation of light propagation in purely bend/splay periodic director deformations. A common occurrence of this type of deformation is encountered in smectic A materials under the Helfrich effect. More importantly, bistable nematic cells with zenithal deformation have been developed for interesting display applications. Both aforementioned deformations are examined to verify the applicability of the proposed periodic BPM.