| 摘要 |
PROBLEM TO BE SOLVED: To provide a light power equalizing device having high instant response performance. SOLUTION: This light power equalizing device is provided with a light intensity modulator 22 as a variable optical attenuator and is constituted so as to feed forward control it with a feedforward control circuit 23. Moreover, a driver amplifier is provided at the output side of the feedforward circuit 23. Furthermore, a light amplifier is connected to the main optical transmission line existing between a light input terminal and a light output terminal. Further, a plurality of sets of light power equalizing devices of a feedforward control system is cascaded. Moreover, the light power equalizing device of a feedback system is connected to the output side of the light power equalizing device of the feedforward system. Also, the input side of the feedback control circuit is connected to the output side of the light intensity modulator and the driver amplifier is controlled with this feedback control circuit. Or, the light intensity modulator is controlled by the average value of the control signal of this feedback control circuit and the control signal of the feedback control circuit. |
