Optical Bragg Scattering from a Polymer-Stabilized Anti-Ferroelectric Liquid Crystal

Abstract

We studied the effect of polymer networks on the temperature dependence of the optical Bragg reflections of an antiferroelectric liquid crystal which forms the chiral ferroelectric (SmC*), intermediate and antiferroelectric (SmC A *) phases. When polymerization is carried out in the SmC* phase, this phase is stabilized at the expense of the intermediate phases and the corresponding Bragg wavelengths follow a non-Landau description. When polymerization is in the SmA phase, the Bragg wavelengths of the SmC* and SmC A * phases are largely temperature independent. The intermediate phases are stabilized at the expense of the SmC* phase in non-radiated samples, which contain traces of the photo-polymer. The range over which the SmC A * is stable is unaffected by polymerization.