An optical modulation device is provided. The optical modulation device includes first and second plates facing each other, a liquid crystal layer interposed between the first and second plates, and first and second electrodes. The liquid crystal layer includes a plurality of liquid crystal molecules. The first plate includes a first aligner. The second plate includes a second aligner. A first alignment direction of the first aligner and a second alignment direction of the second aligner are substantially parallel to each other. The first and second electrodes extend to cross each other. The first and second electrodes are insulated from each other. The second electrode extends to cross the second alignment direction. An angle θP formed between a vertical axis of the second alignment direction and an extending direction of the second electrode is a value between 5° and 45°.