OPTICAL AMPLIFIER

摘要

An optical circulator (4) is inserted at a portion of an optical amplifying fiber (2). Reflecting means (8) is provided to the optical circulator (4) so that wavelength-multiplexed light inputted to the optical amplifying fiber (2) is subject to selection of wavelength by the reflecting means (8), appropriately attenuated by the reflectance set for every wavelength to the reflecting means (8), amplified, and outputted from the optical amplifying fiber (2) as a signal light having no intensity variation between channels.