A beam deflector includes a first electrode layer including a plurality of line electrodes extending in a first direction and arranged parallel to each other in a second direction crossing the first direction; a second electrode layer separated from the first electrode layer by a predetermined distance to face the first electrode layer; and a deflection layer between the first electrode layer and the second electrode layer and having a plurality of optically anisotropic molecules controlled by an electric field formed between the first electrode layer and the second electrode layer. Each of the optically anisotropic molecules has an ellipse shape having a major axis and a minor axis, wherein the major axis is arranged to head for the first direction.