Abstract: A method for controlling the shape and magnitude of the L-band gain spectrum of an erbium doped optical amplifier, in one aspect, involves saturating the amplifier gain with a saturating signal in the L-band. Another aspect of the method involves saturating the amplifier gain by controlling the temperature of the gain medium. By pumping the amplifier in the 980 nm and/or the 1480 nm pump bands, the gain spectra at different inversion levels are adjusted.

Abstract: A method for controlling the shape and magnitude of the L-band gain spectrum of an erbium doped optical amplifier, in one aspect, involves saturating the amplifier gain with a saturating signal in the L-band. Another aspect of the method involves saturating the amplifier gain by controlling the temperature of the gain medium. By pumping the amplifier in the 980 nm and/or the 1480 nm pump bands, the gain spectra at different inversion levels are adjusted.

Abstract: A multi-stage optical fiber amplifier comprises a first gain stage amplifying and optical signal; a pumping source coupled to the first gain stage, a second gain stage coupled to the first gain to further amplifying the optical signal to a desired output signal power, and a second pumping source coupled to the second gain stage. The second pumping source is preferably an erbium-doped fiber laser and has an operating wavelength between about 1520 nm and about 1620 nm. This amplifier achieves good noise figure and high output powers.

Abstract: The optical amplifier includes a first gain medium having an optical host that contains a rare earth dopant and a first pump that supplies optical energy at a first wavelength into this first gain medium. The first pump operates at a pump wavelength that has a lower inversion saturation than the highest wavelength of absorption of the first gain medium. The optical amplifier further comprises a second gain medium operatively coupled to the first gain medium and a second pump that supplies optical energy into the second gain medium.

Abstract: A method of operating an optical amplifier for improved gain and pump-to-signal conversion efficiency in a long wavelength spectral region (L-band) of the emission spectrum of a rare earth doped gain medium having a known pump absorption band involves the steps of providing an optical signal to the amplifier having a large-signal input power; and providing pumping light to the amplifier having a wavelength that is different from a center wavelength of the known pump absorption band for amplifying the optical signal. Signal gain and improved pump-to-signal conversion efficiency was demonstrated for an erbium L-band signal by detuning the pump between about ±0-30 nm on either side of the pump band center wavelength of 979-980 nm. An optical amplifier employing the described method is also disclosed.

Abstract: A multichannel fiber optic communication network incorporates multichannel fiber optical amplifiers having different functions but designed to use substantially identical gain flattening filters. This is achieved by designing the amplifiers to have total insertion losses such that their respective internal gains (internal gain=net gain+total insertion loss) are substantially the same, most preferably within 1 dB.