An optical device according to an embodiment may include: a plurality of light sources configured to emit laser beams; a light direction changing unit comprising at least one of a prism and a mirror, provided on traveling paths of the laser beams, and configured to focus the laser beams at one point by changing travelling directions of the laser beams to form constant angles between the traveling paths of the laser beams; and a scanning mirror configured to perform two-dimensional scanning by reflecting the laser beams received from the light direction changing unit.