Patent ID: 7474459
Filing Date: 2009-01-06
Classification: H01S,H04B

Abstract:
1. A multi-wavelength optical amplifier for amplifying an input wavelength division multiplexed (WDM) optical signal, comprising: a first-stage optical amplifier including an optical fiber amplifying the input WDM optical signal and thereby outputting a first-stage amplified WDM optical signal, and a pump source which pumps the optical fiber so as to have a first gain versus wavelength characteristic; a second-stage optical amplifier including an optical fiber amplifying the first-stage amplified WDM optical signal output from the first-stage optical amplifier and thereby outputting a second-stage amplified WDM optical signal, and a pump source which pumps the optical fiber so as to have a second gain versus wavelength characteristic; and a variable optical attenuator, positioned between the first-stage optical amplifier and the second-stage optical amplifier, attenuating the first-stage amplified WDM optical signal from the first-stage optical amplifier to the second-stage optical amplifier with an optical attenuation value which is varied to control a level of the second-stage amplified WDM optical signal output from the second-stage optical amplifier