Space-charge field induced refractive index modulation in chiral smectic A and C mesophases: A simple model

The Photorefractive properties of chiral smectic A and C phases were studied using a model we had previously developed. The space-charge field induced reorientations considered are due to the electroclinic effect, in the case of the chiral smectic A, and to the reorientation of the spontaneous polarization for the chiral smectic C. The model takes into account both geometrical parameters, like for example light direction and polarization, and material parameters, like birefringence, spontaneous tilt angle or electroclinic coefficient. Results are extremely useful in order to optimize material parameters.