| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical amplifier wherein the utilization efficiency of excitation light is high, the optical amplification efficiency is high, the cost thereof is low, and the miniaturization thereof is possible. SOLUTION: An optical fiber 5, an optical coupler 4a, an erbium-added fiber 3a, an optical coupler 4b, an erbium-added fiber 3b, an optical coupler 4c and an erbium-added fiber 3c, are provided in series in this order in an optical amplification waveguide 2 wherein signal light 11 is wave-guided. Further, an excitation light source 6 is provided, and one optical waveguide 9 is formed of optical fibers 8a to 8c. The optical couplers 4a and 4b output the input signal light 11 to the optical amplification waveguide 2, output a part of the input excitation light 12 to an optical amplification waveguide 3, and output the remaining part thereof to the optical waveguide 9. The optical coupler 4c outputs the input signal light 11 to the optical waveguide 2 and all the input excitation light 12 to the optical amplification waveguide 3. COPYRIGHT: (C)2006,JPO&NCIPI |
