| 摘要 |
PURPOSE:To improve oscillation threshold current and modulation characteristics, by reducing reactive current caused by a parasitic p-n junction, by using a high resistive layer or a p-n junction. CONSTITUTION:High resistive layers 14, 15 are formed between a buried layer 7 and a buffer layer 2 and between the buried layer 7 and a clad layer 6, respectively. When this semiconductor laser is operated, carrier is injected into an active layer 5, by the current flowing from an electrode 11 to an electrode 12 through a contact layer 8, the clad layer 6, the active layer 5, the buried layer 7, and a contact layer 9. By the current flowing from an electrode 13 to the electrode 12 through the buffer layer 2, a modulation layer 3, an isolation layer 4, the buried layer 7, and the contact layer 9, the carrier concentration of the modulation layer 3 is controlled, and the refractive index and the absorption coefficient are changed by plasma effect, thus modulating the laser light. Thereby the useless current caused by a parasitic p-n junction is decreased, oscillation threshold is reduced, and modulation performance is improved. |
