Patent ID: 7170672
Filing Date: 2007-01-30
Classification: H01S,H04B

Abstract:
1. A Raman amplifier for amplifying wavelength division multiplexing (WDM) radiation propagating along an optical fiber, the WDM radiation including a plurality of radiation components each having a selected waveband and power, the amplifier comprising: a) a plurality of optical radiation generating means operable for generating pump radiation of a selected wavelength and power, each optical radiation generating means including a plurality of radiation sources each being operable for generating radiation having the same wavelength but with a different state of polarization, the pump radiation being coupled into the fiber to optically amplify the WDM radiation, the optical radiation generating means being wavelength tuneable; and b) means for measuring the power of the radiation components of the WDM radiation after propagation along the fiber and after amplification to generate measured powers, the wavelength and the power of the optical radiation generating means being controlled in dependence upon the measured powers such as to make the measured powers substantially equal in magnitude and of a selected magnitude.