| 摘要 |
PURPOSE:To reduce optical coupling loss by forming a lens made of a resin using a boundary surface in common together with a reflecting surface on the reflecting surface expanded toward the directions of the transmission and reception of beams in the periphery of a photoelectric conversion element, burying the photoelectric conversion element into the lens and specifying the aperture diameter of said reflecting surface and the height of the lens made of the resin. CONSTITUTION:A recessed section with a circular opening section is formed to the upper surface of a stem electrode 10. A reflecting surface 11 inclined so as to be upward expanded is shaped to the side surface of the recessed section. A light-emitting diode element 12 is die-bonded with the base of the recessed section. A surface electrode for the light-emitting diode element 12 and lead terminals are wire-bonded by extra-fine gold wires. Consequently, the light-emitting diode element 12 incorporated to a stem electrode 10 is buried into the lens 13 shaped by a transmitting epoxy resin having a refractive index of 1.2-1.7. In order to project beams emitted from the light-emitting diode element 12 efficiently to an optical fiber 20, an aperture diameter W is brought to 3mm or less and the aperture diameter W of the reflecting surface is set to the relationship of 1/3H<=W<=2H to the height H of the lens 13 from the surface of the element in relationship with the diameter of the optical fiber 20. Accordingly, the amount of beams radiated to the outside is reduced, thus minimizing loss by coupling. |
