| 摘要 |
<p>The present invention relates to an optical amplifier (10) and the like comprising a structure for effectively suppressing transient output signal power fluctuations caused by delays in control. The optical amplifier (10) including an amplification optical fiber (13) comprises a control system (17) for monitoring, through a light-receiving device (15), power fluctuations in part of light tapped by a branching device (11a) and regulating the power of pumping light outputted from a pumping light source (16). A delay medium (12) is disposed between the branching device (11a) and the amplification optical fiber (13), so as to reduce the difference between the time required for signals transmitted through the branching device (11a) to reach the input end of the amplification optical fiber (13) and the response time of the control system (17), thereby suppressing fluctuations in the output signal level. In particular, the delay medium (12) has an insertion loss of 3dB or less in order to minimize the loss at the input end of the amplification optical fiber (13) so as to ameliorate noise figure.</p> |
