| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber amplifier which suppresses the amplification of spontaneous emission light of a wavelength 0.8μm band, which is a cause for deteriorating the amplification efficiency of the light of the wavelength 1.47μm band, and whose amplification efficiency of the light of the wavelength 1.47μm band is satisfactory. SOLUTION: An optical fiber where thulium and neodymium are added to a core is made to be a gain medium. The spontaneous emission light of the wavelength 0.8μm band, which occurs at the time of optical amplification by thulium, is absorbed by neogim, and the light of the wavelength 1.47μm band is efficiency amplified. |
