Disclosed is an optical assembly including: an upper case which is provided with a first optical path for passing light from a first light source, and a second optical path, which communicates with a side of the first optical path and which introduces the light from a second light source into the first optical path； a lower case coupled with the upper case； and a beam splitter which is disposed in the first optical path, and which maintains a traveling direction with respect to the light from the first light source and changes a direction of the light from the second light source so that the light from the second light source can travel in the same direction as the light from the first light source.
