Liquid crystal grating and holographic display device

A holographic display device, comprising a liquid crystal grating, wherein the liquid crystal grating includes a plurality of grating electrode groups, wherein:

• a grating electrode group of the plurality of grating electrode groups includes a plurality of grating electrodes;
• operation states of the liquid crystal grating include a first mode and a second mode;
• in an operation period of the liquid crystal grating, light is modulated by the liquid crystal grating to obtain deflected light, the liquid crystal grating is switched between the first mode and the second mode, a quantity of the first mode is N1, and a quantity of the second mode is N2, wherein, N1 and N2 are positive integers, and N1>N2;
• and
• in the first mode, a first voltage of a first polarity is provided to a grating electrode of the plurality of grating electrodes, and for one grating electrode group of the plurality of grating electrode groups, an average voltage value of the first voltage is |V1|, and in the second mode, a second voltage of a second polarity is provided to the grating electrode, and for one grating electrode group of the plurality of grating electrode groups, an average voltage value of the second voltage is |V2|, wherein the first polarity is different from the second polarity, and |V1|<|V2|;
• or, in the first mode, a first voltage of a first polarity is provided to a grating electrode of the plurality of grating electrodes, and for one grating electrode group of the plurality of grating electrode groups, a maximum voltage value of the first voltage is |V1max|, and in the second mode, a second voltage of a second polarity is provided to the grating electrode, and for one grating electrode group of the plurality of grating electrode groups, a maximum voltage value of the second voltage is |V2max|, wherein the first polarity is different from the second polarity, and |V1max|<|V2max|.