Light-Scattering Characteristics in Smectic A Liquid Crystals

Abstract

The light-scattering characteristics of smectic A liquid crystals are investigated. In the case of an electrooptic effect, the scattering texture is produced through either the field effect or the current effect. It is found that the textures formed due to this effect give rise to diffusive scattering patterns resulting from multiple scattering in the structure. In the case of a thermooptic effect, the scattering texture is obtained through the phase transition from a nematic to a smectic A phase. The textures formed as a result of the thermooptic effect exhibit higher diffraction peaks correlating to the shape of the domains. The scattering characteristics are found to depend on the process which forms the textures.

Making Smectic Defect Patterns Electrically Reversible and Dynamically Tunable Using In Situ Polymer‐Templated Nematic Liquid Crystals

“…While previous studies reported on light scattering and diffraction properties of other assemblies of SmA FCDs, [ 11–14,19 ] here we observed that linear arrays of EHFCDs could totally hide a background when a linear polarizer of axis P was set parallel to r between the background and the cell (Figure 1d). The haziness could be further reduced by rotating the polarizer; a semitransparent cell was obtained for P perpendicular to r (Figure S1a–c, Supporting Information).…”

“…[ 10 ] FCDs basically consist of two conjugated line defects, the so‐called focal conics, lying in orthogonal planes, around which parallel smectic layers are wrapped. Using different internal structures and self‐organizations of FCDs that can be varied with anchoring conditions, periodic assemblies of FCDs were demonstrated to be scattering systems potentially suitable for display applications, [ 11–14 ] efficient superhydrophobic surfaces, [ 15 ] templates for fabricating microlens arrays, [ 16 ] optically selective photomasks, [ 17 ] matrices for organizing quantum dots, [ 18 ] and polarization‐dependent light diffraction gratings. [ 19 ] While advanced optical functions have been arising from SmA defect patterns owing to their internal ordering, assembly, and combination with guest optical nanomaterials, however, an outstanding issue that prevents from dynamically tuning the optics of these systems remains the structural irreversibility of SmA defect patterns with voltage.…”