A photosensitive monomer of formula. “L1”, “L2”, “L3”, “L4”, “L5”, “L6” are selected from hydrogen, fluorine, chlorine, cyano, alkyl, alkylcarbonyl, alkoxycarbonyl, and alkylcarbonyloxy having 1 to 7 carbon atoms, in which one or more hydrogen atoms may be substituted by fluorine or chlorine.“R1”, “R2”, “R3” and “R4” are selected from hydrogen, fluorine, chlorine, cyano, thiocyanato, pentafluoro sulfanyl, nitrite, straight-chained alkyl/branched alkyl, and a “Z-Sp-P” group. At least one of “R1”, “R2”, “R3” and “R4” is “Z-Sp-P” group. “Z” is selected from oxygen, sulfur, methyoxy, carbonyl, caroboxyl, carbamoyl, methylthio, ethenylcarbonyl, carbonylethenyl, and a single bond. “Sp” is selected from straight-chained alkyl or branched alkyl and a single bond. “P” comprises a polymerizable group.