Patent ID: 7528884

Claim:
An optical device comprising: a base of ring shape with a tapered recess surrounding an opening; an optical chip mounted so that a main surface thereof with an optical element disposed is exposed within the opening of the base when viewed from above; a transparent member attached above an upper surface of the base; and an adhesive layer provided in a gap between the base and the transparent member, wherein the upper surface of the base has a taper so that the thickness of the base becomes thin toward the opening in the tapered recess, and in the region of the tapered recess except for an inner surface of the opening, the distance from a portion of the tapered recess that is located in the upper surface of the base and is joined with the inner surface of the opening to the bottom of the base is smaller than the distance from a portion of the tapered recess that is located in the upper surface of the base other than the portion of the tapered recess that is joined with the inner surface of the opening to the bottom of the base.