A light emitting device includes a first layer that generates light by injection current and forms a waveguide for the light, and an electrode that injects the current into the first layer, wherein the waveguide has a first region, a second region, and a third region, the first region and the second region connect at a first reflection part, the first region and the third region connect at a second reflection part, the second region and the third region extend to an output surface, a longitudinal direction of the first region is parallel to the output surface, and a first light output from the second region at the output surface and a second light output from the third region at the output surface are output in parallel to one another.