The electrooptics of smectic C liquid crystals

Abstract

A theoretical description of the electrodynamical instability for the initial and the fundamental domain regimes in smectic C liquid crystals is presented. On the basis of the bi-axial aspects of the problem, a dependence of the threshold field, charge and curvature relaxation times on the director n tilt angle (ω) were found. It is demonstrated that the electrodynamical instability is a priority of the C₁ type smectics, where the director tilt angle is temperature independent in the smectic C temperature range. It was found that the dielectric reorientation processes are stimulated mainly in C₂ smectics, where the director tilt angle is small and temperature dependent. The role of the sign and the magnitude of the dielectric anisotropy on the character of the electrooptic responses (pure electrohydrodynamic instability, pure dielectric reorientation or a mixture of the two) is discussed.