| 摘要 |
PROBLEM TO BE SOLVED: To provide a light amplifier having the even characteristics of output power against wavelength. SOLUTION: On a light amplification part 10a, an inputted signal light is amplified in a rare-earth doped optical fiber 4, and a signal light, of the wavelength band having large amplification degree, among the signal lights amplified by a light amplification part 10a, is reflected by a fiber grating 12 on an output power equalization part 10b. Then, the reflected light is attenuated by a rare- earth doped optical fiber 13, and the signal light on the wavelength band, having small degree of amplification, is transmitted in that state without attenuating the fiber grating 12. As a result, a signal light, having even wavelength characteristics, can be obtained even when there is irregularity in the output power of the light amplification part 10a. |
