| 摘要 |
PURPOSE:To obtain an optical amplifier applicable to a duplex optical transmission system, regarding an optical amplifier equipped with optical pumping type optical amplification medium (e.g. Er-doped fiber). CONSTITUTION:The optical amplifier consists of the following; a doped fiber 16, an optical circulator 14 having at least three ports, a Y-branch type optical coupler 15 connecting the optical circulator 14 with the doped fiber 16, a laser diode 13 for pumping light, and a means which introduces the pumping light together with a light to be amplified into the optical coupler 15 via the optical circulator. |
