| 摘要 |
PURPOSE:To avoid breakdown in spite of application of a surge voltage on a laser terminal by installation of a laser diode region where laser oscillation takes place and a P-N junction diode disposed in electrically parallel connection with the former on one semiconductor substrate. CONSTITUTION:A sinked double hetero junction laser 11 is formed on a half side of an N type InP substrate 21 and on another half side a reversed surge protecting diode 13 is prepared, and each diode is connected in a parallel arrangment by means of a positive electrode 29 and a negative electrode 30. In this constitution the laser 11 consists of an InGaAsP active layer 23 surrounded by an N type InP layer 25, a P type InP layer 24, a P type InP layer 26 and an N thpe InP layer 27. And the diode 13 consists of an N type InP layer 27 surrounded by a P type InP layer 28, and crossing region of the positive electrode 29 and the negative electrode 30 is insulated by an SiO2 film 31. By this constitution the laser is protected against surge voltages and in addition a low oscillation threshold current is obtained. |
