| 摘要 |
An optical amplifier apparatus using an optical amplifying fiber including a working laser and a stand-by laser for firing pumping light to the optical amplifying fiber through an optical coupler, a signal light monitor unit which splits off part of the output signal light of the optical amplifying fiber by the optical coupler and monitors the same, a drive current monitor unit which monitors the drive current of the working laser, and a supervisory unit which judges that the working laser has deteriorated or there is a fault in the driver circuit of the working laser and switches from the working laser to the stand-by laser to generate the pumping light when the monitor output signal of the drive current monitor unit rises or falls beyond a predetermined range and the monitor output signal of the signal light monitor unit falls below a predetermined value. The level of the output signal light is also referred to in judging the deterioration of the laser for generating the pumping light. |
