| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber amplifier which is inexpensive and small- sized since a Raman fiber is reducible in length and the number of exciting light sources can properly be decreased. SOLUTION: The optical fiber amplifier has a circulator 61, at least two or more erbium-added fibers 11 and 12 which are installed before and behind the circulator 61, an optical fiber 52 which performs Raman amplification of signal light emitted from the circulator 61, a mirror 71 which reflects signal light emitted from the optical fiber 52, exciting light sources 41 and 43 which excite the erbium-added fibers 11 and 12, an exciting light source 42 for Raman amplification which excites the optical fiber, and a multiplexer 22 which multiplexes exciting light from the exciting light source for the Raman amplification with the signal line between the circulator 61 and mirror 71. |
