Q&A of liquid crystal alignment: theory and practice

Abstract

We selected and summarized the most important aspects of liquid crystal alignment. Alignment by the surface profile and flat surface alignment are discussed as the main factors leading to the high-quality orientation of liquid crystals. The advanced level of understanding and formulation allows linking the alignment layer properties to the molecular structure of the alignment material. The paper reviews and combines the latest knowledge about liquid crystal alignment, dwells upon the relationship between the polar and azimuthal anchoring energy, explains the major particularities regarding anchoring measurements in the case of birefringent alignment materials with truly high azimuthal anchoring energy, and observes the current trends of water-friendly alignment materials and their application in geometrical phase device fabrication.

Electrically switchable focus liquid crystal polarization hologram lens

“…There are two important angles (twist and azimuthal) for fabrication of electrically switchable focus liquid crystal polarization lens [3]. The twist angle as it was shown before depends on applied voltage and play the main role in focal length switching (changing of optical phase).…”