Patent ID: 7522334
Filing Date: 2009-04-21
Classification: H04B

Abstract:
1. An optical system comprising: at least one first transmitter; at least one first receiver connected to the at least one transmitter by at least one optical fiber; a first optical amplifier including at least one first pump source to amplify optical signals being transmitted from said first transmitter to said first receiver, wherein said first optical amplifier has a first substantially flat gain profile and associated first noise figure profile over a signal channel wavelength range including said optical signals; at least a second optical amplifier including at least one second pump source configured to amplify optical signals being transmitted from said first transmitter to said first receiver, wherein said second optical amplifier has a second substantially flat gain profile and associated second noise figure profile over the signal channel wavelength range including said optical signals, a first gain profile varying device in combination with said first optical amplifier such that said first gain profile is varied to a non-flat first gain profile and to a non-flat first noise figure profile; and a second gain profile varying device in combination with said second optical amplifier such that said second gain profile is varied to a non-flat second gain profile and to a non-flat second noise figure profile, such that a composite noise figure profile of the first and second non-flat noise figure profiles is substantially flat over the signal channel wavelength range and differs from a composite noise figure profile when the first and second gain profiles are substantially flat over the signal channel wavelength range.