OPTICAL AMPLIFIER AND OPTICAL SURGE SUPPRESSION METHOD

PROBLEM TO BE SOLVED: To suppress optical surge to improve optical transmission quality. SOLUTION: An optical amplification section 11 excites an amplification medium 11a in which an active substance for optical amplification is doped, and optically amplifies it. A light receiving element 12 receives an output from the optical amplification section 11. A semiconductor optical amplifier 13 is installed between the optical amplification section 11 and the light receiving element 12. An input light level adjusting section 14 adjusts the level of the input light of the semiconductor optical amplifier 13. A driving section 15 supplies a driving current for adjusting the level of output light of the semiconductor optical amplifier 13 to the semiconductor optical amplifier 13. In addition, the driving section 15 supplies a driving current in such a range that the maximum output light level of the semiconductor optical amplifier 13 does not exceed the maximum input light level of the light receiving element 12. An input light level adjusting section 14 sets the level of input light for the amplification characteristic of the semiconductor optical amplifier 13 to be amplified by the supplied driving current so that the operating point of the semiconductor optical amplifier 13 may be adjacent to a boundary between a non-saturation area and a saturation area. COPYRIGHT: (C)2010,JPO&INPIT