Low Driving Voltage and Analysis of Azobenzene Polymer Doped Liquid Crystal Grating

We mix azobenzene polymer and liquid crystal in certain ratio. Then the mixture is injected into cells. Nonlinearly photoinduced birefringence takes place when linearly polarized ultraviolet is applied with the pattern photomask covering on the cells, which results in the formation of azobenzene polymer doped liquid crystal grating. The obtained grating is characterized by an optical microscope and a He--Ne laser. The results indicate that the samples have clear grating structure, and the diffraction efficiencies can be modulated by electric field. The sample driving voltage is 0.6 V/μm. It is lower than the driving voltage of holographic polymer dispersed liquid crystal transmission grating and could be matched with the driving integrated circuit.