An optical apparatus includes an illumination module, a first structured light generation module, a second structured light generation module and a beam splitting unit. The beam splitting unit is arranged between the illumination module, the first structured light generation module and the second structured light generation module. When a source beam from the illumination module is received by the beam splitting unit, the source beam is split into a first light beam and a second light beam. The first light beam is propagated in a direction toward the first structured light generation module. The second light beam is propagated in a direction toward the second structured light generation module. After the first light beam passes through the first structured light generation module, a first structured light is generated. After the second light beam passes through the second structured light generation module, a second structured light is generated.