An optical scanning device includes a light source configured to emit first light in a first wavelength range and second light in a second wavelength range, a beam divider configured to allow the first light to travel in a first direction, and receive the second light, and allow the second light to travel in a second direction different from the first direction, a first optical modulator configured to receive the first light, and modulate a phase of the first light received by the first optical modulator to change a travelling direction of the first light received by the first optical modulator, and a second optical modulator configured to receive the second light, and modulate a phase of the second light received by the second optical modulator to change a travelling direction of the second light received by the second optical modulator.