Optical device having a substrate and a laser unit that emits light into the substrate

An optical device comprising:

• a first substrate, formed of a semiconductor material and having a first surface and a second surface which is a rear surface of the first surface, the first substrate comprising:
• a laser unit, having an active layer laminated between the first surface and the second surface and emitting light into the first substrate from the active layer;
• a reflecting mirror, having a plane obliquely intersecting an optical axis of light emitted from the laser unit, provided on the first surface reflecting the light emitted from the laser unit and propagating toward the second surface;
• and
• a convex lens, provided in a region on the second surface, the region including an optical axis of the light reflected by the reflecting mirror;
• and
• a second substrate, having a third surface facing the second surface, and being provided with a grating coupler and an optical waveguide on the third surface thereof, the optical waveguide having light incident on the grating coupler propagating therethrough,
• wherein the optical axis of the light reflected by the reflecting mirror obliquely intersects an optical axis in a center of the convex lens, and
• wherein an optical lens of light passing through the convex lens and being incident on the grating coupler obliquely intersects a normal direction of the grating coupler.