| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system capable of reducing speckles by highly accurately combining split light rays.SOLUTION: An optical system includes: a first phase diffraction grating which is disposed in a light path of light emitted from a light source unit to split the light path of incident light into a plurality of light paths before outputting the light; a second phase diffraction grating which combines the plurality of split light rays traveling on the plurality of light paths and entering the second phase diffraction grating; and a light path length difference adjuster which adjusts difference in light path length from the first phase diffraction grating to the second phase diffraction grating among the plurality of split light rays.SELECTED DRAWING: Figure 1 |
