| 摘要 |
PROBLEM TO BE SOLVED: To provide a light amplifier that is able to be operated so as to lessen error.SOLUTION: A light amplifier comprises: a light variable attenuator 3 arranged between first and second light amplifying sections 1 and 2; and a control section 4 that controls the first and second light amplifying sections and the light variable attenuator. The control section feedback controls the first light amplifying section such that the gain of the first light amplifying section has a first target gain. The first light amplifying section is feed-forward controlled on the basis of a first input light detection value supplied to the first light amplifying section. The excitation light source of the second light amplifying section is feedback controlled such that the gain of the entire light amplifying device has the second target gain. Also, the second light amplifying section is feed-forward controlled on the basis of a second input light detection value supplied to the second light amplifying section. The light variable attenuator is feedback controlled such that an amount of light attenuation of the light variable attenuator has a target amount of light attenuation. By correcting the control parameters of the second light amplifying section and the target amount of light attenuation of the light variable attenuator, the gain tilt of the entire light amplifier 100 is corrected. |
