| 摘要 |
<P>PROBLEM TO BE SOLVED: To protect an optical amplifier when an interference is generated in its transmitting signal-light. <P>SOLUTION: In the case of so controlling an optical amplifier automatically as to keep its output power constant, a pumping-light power is suppressed when the input-light power of an amplification-oriented optical fiber 13 is not larger than a predetermined value, and the pumping-light power fed from a pumping-light source 16 to the amplification-oriented optical fiber 13 is not smaller than a predetermined value. Consequently, the optical amplifier can be protected while avoiding the stopping of an optical transmission, except for the unavoidable cases considered from the view-point of the protection of an apparatus. <P>COPYRIGHT: (C)2004,JPO |
