摘要 |
PROBLEM TO BE SOLVED: To efficiently amplify signal light to desired optical power in multiple stages without wasting excitation energy for amplification of Raman scattered light. SOLUTION: The amplifying device is provided with a plurality of optical amplification systems A1, A2 and A3 which stepwise amplify signal light by using rare earth addition optical fibers 8, 10 and 13. BPF9b, 12b and 15b are arranged in respective post-stages of a plurality of the optical amplification systems A1, A2 and A3. BPF9b, 12b and 15b make signal light amplified by the optical amplification systems A1, A2 and A3 pass, and remove Raman scattered light caused by amplified signal light. COPYRIGHT: (C)2007,JPO&INPIT |