| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical amplifier that can set the light intensity of signal light per wavelength that is contained in wavelength multiple signal light to a fixed level, and at the same time, can reduce fluctuation in the light intensity of each wavelength light that is contained in the wavelength multiple signal light by a simple configuration, even if the light intensity of the wavelength multiple signal light entering the optical amplifier is changed. SOLUTION: The wavelength multiple signal light is amplified in a rare earth doped optical fiber 21 for dividing by a photocoupler 24. One of a specific wavelength signal light that is contained in the divided wavelength multiple signal light, and has specific wavelength is extracted by an optical filter 30. A variable optical attenuation part 11 is controlled by a variable optical attenuation control part 12, to make constant the light intensity of the extracted specific wavelength signal light. |
