OPTICAL SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical semiconductor device that is lessened in size and thickness. SOLUTION: Laser rays emitted from a first semiconductor chip 13 are reflected from a plane 17. The reflected light from the plane 17 are projected form the upside of a resin-sealed body 16. A monitoring semiconductor chip 15 receives the transmitted light that passes through the plane 17 so as to monitor its intensity. Furthermore, external light impinging on the plane 17 of the resin-sealed body 16 is detected by a receiving semiconductor chip 14, passing through the plane 17.