63.1: Invited Paper: Liquid Crystal Devices Based on Photo‐Alignment and Photo‐Patterning Materials

Abstract

Liquid crystal devices based on photo-alignment and photo-patterning materials, were proposed, including patterned retarders for 3D applications, lenses with electrically tunable focal distance, LC based sensors, switchable q-plates, and optically rewritable E-paper. The photoalignment materials were mostly photosensitive azodye layers. The combination of azo-dye layers and liquid crystal polymers were also used for photo patterned phase retarders. The practical applications of new LC elements in 3D displays and other LC technology areas are envisaged.

Photoalignment of liquid crystals: basics and current trends

“…Also, one can readily pattern LC alignment that allows one to realize patterned retarders and polarizers particularly needed for development of stereoscopic and transflective LCDs. [160][161][162][163][164][165][166] Examples of photonic devices based on the photoaligned layers of LCs are electrically controlled Fresnel lenses, [167][168][169] polarization convertors, 170,171 and optical gratings. [172][173][174][175][176][177][178] The possibility of aligning LCs by light in micro-volumes opens new horizons for their applications in miniature LC telecommunication devices such as waveguides, optical switches and routers, etc.…”

Photoalignment of Liquid Crystals: Applications to Fast Response Ferroelectric Liquid Crystals and Rewritable Photonic Devices

“…8 New photoalignment materials that can be potentially used in the photoaligning technology for LCDs were developed. 9 A fast-switching FLC with V-shape switching, i.e., a number of gray scales, can be used for field sequential colors (FSC) FLC-LCD. In this case, we need FLC with a sufficiently low spontaneous polarization and fast switching.…”

Photo-Alignment Technology

“…The direction of alignment can be altered by exposing the LC again to UV. Owing to such features of photoalignment as the absence of ion and impurity problems, rewritability, usability on flexible and curved surfaces, ease of patterning, the spatially distributed optical axis orientation and control of the pretilt angle and anchoring energy, it has been extensively applied to fabricate LC-based optical devices that cannot be formed by conventional rubbing [20]. Here we introduce some applications of surface-mediated photoalignment.…”