| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical amplifier reliably detecting the interruption of input light, and to provide a control method and a control program. SOLUTION: When an input light level is less than a predetermined level, a high-speed response measure is unnecessary and the improvement of detection accuracy is required, since a reverse bias voltage of a photodiode 3 is lowered, a dark current is reduced and also a minimum response frequency required for monitoring a low input is allowed to be a low frequency, so that the monitoring accuracy of input light can be improved while suppressing a reduction in a response speed, and the interruption of input light can be reliably detected. When the input light level is not less than the predetermined level and the high-speed response measure is required, since the reverse bias voltage is increased, the inter-terminal capacitance of the photodiode 3 is reduced and a minimum response frequency required for a high-speed response is also increased, so that the response speed can be improved while suppressing the reduction in the monitoring accuracy of the input light and also the interruption of the input light can be reliably detected. COPYRIGHT: (C)2010,JPO&INPIT |
