| 摘要 |
PURPOSE:To provide an optical fiber amplifier which can transmit monitor control signal light without increasing the number of components where main signal light passes. CONSTITUTION:The port C of an optical circulator 12-1 is connected to one end of an Er-doped optical fiber 11, a photodetector 15-1 to the port D, and a light source 14 to the port A, so that the port B serves as the input port of main signal light; and the port A of an optical circulator is connected to the other end of the Er-doped optical fiber 11, so that the port B serves as the output port of main signal light, a photodetector 15-2 is connected to the port C, and an excitation light source 13 to the port D. Monitor control signal light is sent from the light source 14 in a direction reverse to that of main signal light, monitor control signal light sent from a direction reverse to that of the main signal light is received by the photodetector 15-2. |
