Liquid crystal Fresnel lens display

A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display(LCFLD) with a holographic screen was demonstrated.The proposed display system has high efficiency,simple fabrication,and low manufacturing cost due to the absence of a polarizer and color filter.     

Effect of fluorine groups and different terminal chains on the electro-isomerization of azobenzene liquid crystals

A series of azobenzene liquid crystals with one or two terminal acrylate groups were synthesized and their polymers were fabricated.The azobenzene liquid crystals and their polymers achieved the photoisomerization from the liquid crystalline trans-isomer to the isotropic cis-isomer with UV irradiation.Then,the cis to trans isomerization induced by an electric field was studied,the time required for electro-isomerization was measured,the texture change and absorption variation from cis to trans form induced by the electric field were observed clearly,and the time required for electro-isomerization was much shorter than that for thermal relaxation.The influence of the polar group(fluorine),terminal acrylate group,and flexible alkyl chain on the time of electro-isomerization was studied.The results show that the compounds with polar fluorine group require shorter time for electro-isomerization and the polymerization of terminal acrylate group delays the electro-isomerization.