Patent ID: 6122298
Filing Date: 2000-09-19
Classification: H01S

Abstract:
An optical amplifier comprising:a rare earth doped optical fiber producing an amplified optical signal upon optical pumping of said rare earth doped optical fiber at a pumping energy characterized by a pumping wavelength, said pumping wavelength falling within a band of wavelengths effective to supply said pumping energy to said rare earth doped optical fiber;a second optical fiber; andfirst and second optical sub-pump sources optically coupled to said rare earth doped fiber by said second optical fiber, said first and second optical sub-pump sources generating first and second optical spectra centered at a first and a second wavelength, respectively, and said sub-pump sources collectively supplying a given amount of power to said rare earth doped optical fiber;said first and second wavelengths generated by said sub-pump sources being within said band of effective wavelengths such that each of said first and second optical spectra provides a substantial portion of said pumping energy to said rare-earth doped optical fiber;wherein Raman gain collectively generated by propagation of said first and second optical spectra along said second optical fiber is less than that which would have been generated by propagation of a third optical spectrum centered at a single peak wavelength within said band of effective wavelengths for supplying said given amount ofoptical power to said rare earth doped optical fiber.