Patent ID: 6977951

Claim:
A semiconductor laser apparatus comprising: an insulating frame in which at least a semiconductor laser device and a light receiving device are mounted; and a plurality of leads passing through each of two opposite faces of the insulating frame and extending from inside to outside of the insulating frame, wherein the insulating frame has external faces that are parallel to a mounting face on which the semiconductor laser device is mounted, and the insulating frame has a protruding portion protruding vertically against the mounting face for continuously surrounding at least the semiconductor laser device mounted on the mounting face, and wherein the protruding portion has two opposite cylindrical faces having a common center axis which is aligned with an optical axis of the semiconductor laser device and is displaced from a center of external shape of the insulating frame, thereby each of the two cylindrical faces have an asymmetric shape in relation to a plane that includes the optical axis of the semiconductor laser device and is parallel to the plurality of leads.