| 摘要 |
PROBLEM TO BE SOLVED: To provide a high performance optical fiber amplifier having simple structure in which the loss of signal light is reduced at an input stage while decreasing the number of components of a beam splitter thereat by providing an optical multiplexer/demultiplexer with an optical signal light detector. SOLUTION: Since a pumping light and signal light leak out while being multiplexed from a port 4, an optical filter 11 for blocking the pumping light is provided only for the purpose of monitoring an input signal light thus monitoring only the input signal light by means of a photodetector 6. A pumping light and an input signal light multiplexed through a fused optical fiber optical multiplexer/demultiplexer 3 is inputted from the port 3 thereof to an optical fiber added with a rare earth element and the signal light is subjected to induction discharge effect and amplified. The amplified signal light passes through an optical isolator and a beam splitter before being outputted from an output optical connector. The beam splitter is provided with a photodetector for monitoring the amplified signal light so that feedback to a pumping light source can be promoted. |
