| 摘要 |
PROBLEM TO BE SOLVED: To attempt reduction of excitation light power when using a small number of channels, e.g., at an initial introduction time, thus attempting the reduction of an excitation light source cost that accounts for a major portion of an optical amplifier cost when using a small number of channels, e.g., at an initial introduction time. SOLUTION: An optical amplifier 1 is provided with a Raman amplifiying part 2 that can amplify signal light of a full band consisting of an amplification band for a rare-earth doped fiber amplifier and a band for a tolerated number A of channels that is outside the amplification band, a rare-earth doped fiber amplifier part 8 that is prepared when the number of used channels is more than the tolerated number A of channels, and a controlling part 7. The controlling part 7 is made up so as to control an excitation light wavelength from the Raman amplifying part 2 such that the full-band signal light is amplified when the number of used channels is the tolerated number A of channels or less while on the other hand it controls the excitation light wavelength from the Raman amplifying part 2 such that the signal light in a band outside the amplification band of the rare-earth doped fiber amplifier is amplified when the number of used channels is more than the tolerated number A of channels. COPYRIGHT: (C)2006,JPO&NCIPI |
