Patent ID: 7139120

Claim:
An optical amplifier comprising: an amplification medium for amplifying wavelength-division-multiplexed (WDM) light passed through an upstream transmission line using an excitation light; a measurement part for measuring both of optical power of said WDM light inputted to said amplification medium and optical power of said WDM light outputted from said amplification medium; a variable gain equalizer connected to a downstream transmission line and capable of variably gain equalizing of said WDM light amplified by said amplification medium; a database for holding loss-wavelength characteristics data according to a plurality of transmission line types and gain-wavelength characteristics data according to a plurality of amplifying medium types with an input optical power and an output optical power as parameters; an arithmetic part for computing an inverted characteristic of passing-wavelength characteristic of said transmission line and said amplification medium, on the basis of said loss-wavelength characteristic data according to a type of said transmission line held in said database and said gain-wavelength characteristic data according to a type of said amplification medium specified by said parameters, held in said database; and a setting part for setting a passing-wavelength characteristic of said variable gain equalizer to said inverted passing-wavelength characteristic computed by said arithmetic part.