| 摘要 |
PROBLEM TO BE SOLVED: To provide a light amplifier which is equipped with a plurality of stages of light amplifier portion and is capable of high speed control with a simple configuration, and to provide its control method. SOLUTION: The light amplifier 1 is that which carries out optical amplification of a light signal inputted to an input terminal 11, and outputs it from an output terminal 12. The amplifier is equipped with N stages light amplifiers 21<SB>1</SB>-21<SB>N</SB>, (N-1) optical attenuators 22<SB>1</SB>-22<SB>N-1</SB>, N excitation light sources 23<SB>1</SB>-23<SB>N</SB>, (N-1) attenuation ratio control units 24<SB>1</SB>-24<SB>N-1</SB>, an input light monitor 31, an output light monitor 32, and a controller 41. The controller 41 carries out feedback control of a drive current supplied to a laser diode included in each excitation light source 23<SB>n</SB>based on an input light power obtained from the monitor by the input monitor 31, an output light power obtained from the monitor by the output light monitor 32, and the target value of the whole light amplification ratio. COPYRIGHT: (C)2007,JPO&INPIT |
