| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical amplifier that is suitable to overcome one or more defects occurring when a WDM signal has many WDM channels.SOLUTION: There are provided an optical amplifier 1 and a relating optical amplification method. The optical amplifier 1 has an optical path 2 having an input terminal 3 and an output terminal 4, a first erbium-added optical fiber 5 disposed along the optical path, a first gain flattening filter 6 disposed at the downstream side of the first erbium-added optical fiber along the optical path, a second erbium-added optical fiber 7 disposed at the downstream side of the first gain flattening filter along the optical path, a second gain flattening filter 8 disposed at the downstream side of the second erbium-added optical fiber along the optical path, a third erbium-added optical fiber 9 disposed at the downstream side of the second gain flattening filter along the optical path, and an optical pump 10 which is optically coupled to the optical path so as to optically excite at least the first and third erbium-added optical fibers. |
