Applications of liquid crystal planer optical elements based on photoalignment technology in display and photonic devices

Birefringence and Orientation Direction Control of Photoalignable Liquid Crystalline Copolymer Films Based on In Situ Modification of Mesogenic Groups

“…Photoalignment has been investigated to fabricate liquid crystal (LC) displays, − holography and optical films, − and polarization sensitive diffraction devices. − Thin photosensitive polymeric films, which include azobenzene or photo-cross-linkable moieties, are frequently applied to the photoalignment layer using linearly polarized (LP) light exposure. These films produce a very small birefringence (Δ n ) via an axis-selective photoreaction employing LP light when molecular reorientation does not occur …”

“…Diverse optical devices have been realized by combining curable LC materials on the photoalignment layer. Examples include patterned birefringent films and polarized diffraction devices. ,− Alternatively, photoalignable LC polymers (PLCPs) form their own molecularly oriented structure via LP light exposure. The LP light exposure is often followed by thermal stimulation. − ,, Several types of PLCPs have been developed.…”