| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical amplifier which can suppresses a change in gain due to variation of oscillating wavelength in a stimulating light source. SOLUTION: This optical amplifier is provided with a rare-earth-doped optical fiber 13 to which a rare earth element having a function to amplify a signal light through optical stimulation is added, a stimulating light source to output a stimulation light for the fiber 13, and optical demultiplexer/multiplexer 11a and 11b to demultiplex and multiplex the output light and signal light from the stimulation light source. The stimulation light sources 10a and 10b are provided at even number, and a half thereof (stimulating light source 10a) is allowed to oscillate at a shorter wavelength than the stimulation wavelength showing a peak of gain in the fiber 13, while the other half (stimulation light source 10b) is allowed to oscillate at a longer wavelength than the stimulation wavelength showing a peak of gain in the fiber 13. |
