An optical modulation device includes a first plate, a second plate, and a liquid crystal layer. The first plate includes a first substrate, a lower plate electrode formed on the first substrate, a first electrode layer, and a first aligner. The first electrode layer and the first aligner are formed on the lower plate electrode. The second plate faces the first plate. The second plate includes an upper plate electrode and a second aligner. The liquid crystal layer is disposed between the first plate and the second plate. The liquid crystal layer includes a plurality of liquid crystal molecules. An alignment direction of the first aligner and an alignment direction of the second aligner are substantially parallel with each other.