| 摘要 |
PURPOSE:To reduce the variation in light amplification gain, and to lessen the distortion of waveform of a signal light by providing an attenuation means with which the signal light amplified by the main body of a light amplifier is outputted by attenuating it with almost complementary wavelength characteristics against the wavelength characteristics of the light amplification gain of the light amplifier main body. CONSTITUTION:The signal light made incident on one end of an Er-doped fiber 46 through the intermediary of an optical fiber coupler 26 is amplified by the induced emission of the exciter Er. The amplified signal light is taken out to an output end through an optical filter 56. As the transmission characteristics of the optical filter 56 has complementary wavelength dependency, the distortion of wavelength of the signal light, caused by the wavelength dependency of light amplification gain on the optical fiber 46, can be compensated. To be more precise, the variation in light amplification gain, caused by the microscopic variation of wavelength of the signal light inputted to the main body part of a light amplifier 6, can be removed by the working of the filter 56, the distortion of wavelength of the signal light outputted from the light amplifier is reduced, and the high degree of noise component generated on the light amplifier can also be decreased. |
