Patent ID: 6959149

Claim:
A method of balancing the power level of an optical signal within an aggregate of optical signals in an amplified dense wavelength division multiplexing DWDM optical network having an optical link extending between an optical signal transmitter and an optical signal receiver, said optical signal transmitter associated with a multiplexer following it on along said optical link, said optical signal receiver associated with a multiplexer preceding it along said optical link, said optical link having one or more optical fibers spans, some of the optical fiber spans having an optical amplifier and variable optical attenuator VOA, said method comprising: measuring the power level of the optical signal received at the receiver through the optical link and referencing said measured receive power level to a nominal power level in the multiplexer immediately preceding the receiver; measuring the power level of the optical signal at the optical transmitter and referencing said measured transmit power level to a nominal power level in the multiplexer immediately following the transmitter; calculating a mean power level of the optical signal from said optical measurements, the mean power level of the optical signal being the mean of the power levels of the optical signal at the transmitter and at the receiver referenced to the nominal power levels in the associated multiplexers; and adjusting the mean power level of the optical signal independently of the power levels of other optical signals carried on the same optical link to the receiver so that a desired OSNR at the receiver is achievable.