| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized optical device that secures an alignment tolerance when it is connected to an optical element, can multiplex a plurality of lights, and can suppress the spread of a projection image.SOLUTION: The optical device includes: a light propagation unit 3 that is disposed on a first cladding layer 2, has a refractive index higher than that of the cladding layer 2, and has a gradually decreasing vertical cross section in the light propagation direction from a light incident part 7 to a light emission part 8; and a lens 4 that is disposed backward in the light propagation direction of the light emission part 8 and substantially collimates or condenses the light from the light emission part 8. |
