| 摘要 |
PURPOSE:To provide an optical fiber amplifier in which the generation of distortion due to the wavelength dependency of gains erbium-doped fiber(EDF) is minimized. CONSTITUTION:In an optical fiber amplifier provided with EDF 2 and 5, which amplifies a signal light by the input of excitation light, and light sources 8 and 9 which generate an excitation light, a plurality of EDF 2 and 5 are series- arranged in such a manner that the signal light is passed through the EDF 2 and 5 successively. Pertaining to the wavelength dependency of gains of the EDF, as its characteristics are shifted by the intensity of the signal light or the excitation light, the intensity of the signal light inputted to the series- arranged EDF increases on the EDF arranged at the back. Therefore, the gain wavelength dependency of the front EDF 2 and the gain wavelength dependency of the back side are cancelled with each other, and the distortion generated by the wavelength dependency can be suppressed. |
