SEMICONDUCTOR LIGHT RECEIVING/EMITTING ELEMENT AND PHOTOCOUPLER USING IT

PURPOSE:To obtain a photocoupler which has a small size and can be assembled easily. CONSTITUTION:An active layer 15 working as a light emitting section and light receiving area 16 working as a light receiving section are formed on the same light receiving/emitting surface 19 of the title element 10. An optical fiber 27 is arranged opposed to the surface 19 and a lens system 31 composed of condenser lenses 28 and 30 is interposed between the fiber 27 and element 10. An inlet- and outlet-side cores 32a and 32b are formed on the light coupling end face 33 side of the fiber 27 by branching the core 32 of the fiber 27. The laser light emitted from the active layer 15 is made incident to the core 32a through the lens system 31 and transmitted through the core 32. The light transmitted from the opposite side is introduced to the light receiving area 16 from the core 32b through the system 31.