A liquid crystal grating includes a liquid crystal layer arranged between a first substrate and a second substrate; a quantum dot layer including a plurality of sub-pixels distributed in an array, each of the sub-pixels includes a light-shielding region located at a central portion of the sub-pixel and a quantum dot region that is separate from the light-shielding region; an electrode structure distributed across the plurality of sub-pixels; and a light input layer defining a plurality of light input ports each arranged opposite to the light-shielding region of a respective one of the sub-pixels. The electrode structure is configured to change light transmission of the liquid crystal layer depending on control voltages applied to the electrode structure.