Patent ID: 7202997
Filing Date: 2007-04-10
Classification: H01S,H04B

Abstract:
1. An optical amplifier comprising: an optical coupler to branch an input light; a first optical amplifier unit to amplify one of the branched light of the optical coupler; a first variable optical attenuator to attenuate an output of the first optical amplifier unit; a second optical amplifier unit to amplify an output light of the first variable optical attenuator; a second variable optical attenuator to attenuate another branched light of the optical coupler; a first control unit to control gains of the first and second optical amplifier units based on an output of the second variable optical attenuator and an output of the second optical amplifier unit; and a second control unit to control attenuation quantities of the first and second variable optical attenuators based on the input and the output of the first optical amplifier unit and an input and the output of the second optical amplifier unit.