Raman amplifier and optical transmission system using the amplifier

摘要

A plurality of pump lights are appropriately located in a wavelength band lambd1 to lambd3. The width of the wavelength band lambd1 to lambd3 is wider than a Raman shift amount. Gain is obtained in a wavelength band lambd2 to lambd3 by the plurality of pump lights located in the wavelength band lambd1 to lambd2. Gain is obtained in a wavelength band lambd3 to lambd4 by the plurality of pump lights located in the wavelength band lambd2 to lambd3. As a result, gain can be obtained in a wavelength band lambd2 to lambd4. A plurality of signal lights are located in the wavelength band lambd2 to lambd4. The deviation of gain can be adjusted by controlling the power of each of the plurality of pump lights.