| 摘要 |
PURPOSE:To provide an optical amplifier in which the mismatching of a refractive index is hardly caused even when a fiber whose refractive index is different from an ordinary refractive index is connected, in which a relative-intensity noise is hardly degraded and in which the transmission quality of an optical transmission system as a whole is hardly lowered. CONSTITUTION:The optical amplifier is constituted in such a way that an optical fiber 4 in which the refractive index of a core is changed continuously in the length direction is connected across an optical fiber 2 on both sides of the incident side and the radiant side or on one side of a fiber 1 for optical amplification and an optical fiber 3 which is connected to it. |
