| 摘要 |
PURPOSE:To obtain an integrated element of photo semiconductor wherein a leak current between adjacent photo semiconductor elements is small, by forming an epitaxial layer of high resistivity possessing a wave guide structure between photo semiconductor elements. CONSTITUTION:A semiconductor laser 11 and a photo detector 12 are formed on an n-InP substrate 20, and a coupling waveguide part 13 composed of a high resistive epitaxial layer are formed between the semiconductor laser 11 and the photo detector 12. Therefore a signal voltage of about +2V applied to the semiconductor laser and a voltage of about -6V applied to the photo detector 12 are separated with each other, so that a leak current does not flow. As for the coupling waveguide part 13, is waveguide is constituted of an InP layer 22 of low reflectivity and an InGaAsP layer 23 of high reflectivity so that the laser light emitted from the semiconductor laser is coupled to the photo detector 12 with low loss. |
