A semiconductor device includes a light emitting element comprising a substrate having a first and a second surface and an outer edge connecting the first and second surfaces. A light emitting layer is on a central portion of the first surface but not on a peripheral portion between the central portion and the outer edge of the substrate. A first insulating layer is disposed on the peripheral portion of the first surface, a side surface of the light emitting layer, and a third surface of the light emitting layer that is spaced from the first surface of the substrate. A first electrode is electrically contacting the third surface of the light emitting layer. A light receiving element is provided in a propagation path of light emitted from the light emitting element.