Patent ID: 7281860

Claim:
An optical transmitter comprising: a substrate having an opening; a submount attached to the substrate and having a through hole; and a light-emitting element disposed on a rear surface of the submount and having a light-emitting portion, the through hole having an inner wall, the through hole having an inside diameter increasing from a rear surface side of the submount toward a front surface side thereof, the light-emitting element disposed so that the light-emitting portion is exposed within the through hole, the light emitting portion radiating light beams toward the opening of the substrate, the through hole being such that part of the light beams goes out the through hole and enters the opening of the substrate without being reflected, and that the other light beams goes out the through hole into the opening of the substrate after being reflected from the inner wall thereof, wherein a difference in linear expansivity between the submount and the light-emitting element is set smaller than a difference in linear expansivity between the substrate and the light-emitting element; the submount is made of silicon, the silicon anisotropically etched to form the through hole; the substrate is a lead frame for providing a connection to an outside electric circuit; and the light-emitting element includes an electrode provided around the light-emitting portion, the electrode electrically connected to the rear surface of the submount.