Abstract: An optical transmission link pumped with multiple orders Raman pumps on both ends of the link is disclosed. At least one first-order Raman pump and at least two higher-order Raman pumps are provided on each end for reducing optical power variation of the optical signal along the optical transmission link. Wavelengths and optical power levels of the multiple-order Raman pumps and the additional Raman pump(s) can be selected by computer simulation to lessen the spatial optical power variation of the optical signal.

Abstract: An optical transmission link pumped with multiple orders Raman pumps on both ends of the link is disclosed. At least one first-order Raman pump and at least two higher-order Raman pumps are provided on each end for reducing optical power variation of the optical signal along the optical transmission link. Wavelengths and optical power levels of the multiple-order Raman pumps and the additional Raman pump(s) can be selected by computer simulation to lessen the spatial optical power variation of the optical signal.

Abstract: A change in loading conditions of fiber amplifiers in an optical communications network causes rapid variations in the gain profile of the amplifiers due to spectral hole burning and stimulated Raman scattering. An apparatus for reducing such gain profile variations is described which monitors optical signal perturbations and reacts by adjusting pump powers of the amplifiers and, or fast variable optical attenuator according to a pre-determined function stored in the form of constants in controller's memory. The optical signal is monitored as total power, and the power of light after passing through one or more optical filters. The light detection is relatively fast, whereby the gain profile variations are compensated by fast controlled variable optical attenuator and pump power adjustment upon the change in loading conditions.

Abstract: A reconfigurable optical amplifier is formed of a plurality of optical switches and a plurality of fiber amplifier sections to provide a switchable amplifying network. A variable pump splitter provides pump light from an optical pump source to two or more fiber amplifier sections. The optical switches and variable pump splitters are formed in a planar lightwave circuit, which may further include pump WDM combiners, variable optical attenuators, tap couplers and other optical components, and to which monitoring photodiodes and the fiber amplifier sections are coupled. A same PLC can be used for a wide variety of reconfigurable optical amplifiers.

Abstract: An optical amplifier having two erbium doped fiber coils and a pump laser diode is described. A tunable optical power splitter is used for variably splitting the optical pump power for the laser diode between the two erbium doped fiber coils, and variable tilters can be used for correcting the gain tilt of the amplifier. The variable splitter and the tilters can include thermally tunable Mach-Zehnder interferometers.

Abstract: An optical amplifier having two erbium doped fiber coils and a pump laser diode is described. A tunable optical power splitter is used for variably splitting the optical pump power for the laser diode between the two erbium doped fiber coils, and variable tilters can be used for correcting the gain tilt of the amplifier. The variable splitter and the tilters can include thermally tunable Mach-Zehnder interferometers.

Abstract: A fiber amplifier having two erbium doped fiber coils and a pump laser diode optically coupled, through a fiber array, to a planar lightwave circuit, is described. A photodetector array, a multiport free-space optical isolator, and a strip of thin-film gain flattening filter are attached to a side surface of the planar lightwave circuit, which has a tunable optical power splitter for variably splitting the optical pump power for the laser diode between the two erbium doped fiber coils, and variable tilters for correcting the gain tilt of the amplifier. The variable splitter and the tilters are thermally tunable Mach-Zehnder interferometers.

Abstract: A change in loading conditions of fiber amplifiers in an optical communications network causes rapid variations in the gain profile of the amplifiers due to spectral hole burning and stimulated Raman scattering. An apparatus for reducing such gain profile variations is described which monitors optical signal perturbations and reacts by adjusting pump powers of the amplifiers and, or fast variable optical attenuator according to a pre-determined function stored in the form of constants in controller's memory. The optical signal is monitored as total power, and the power of light after passing through one or more optical filters. The light detection is relatively fast, whereby the gain profile variations are compensated by fast controlled variable optical attenuator and pump power adjustment upon the change in loading conditions.

Abstract: A change in loading conditions of fiber amplifiers in an optical communications network causes rapid variations in the gain profile of the amplifiers due to spectral hole burning and stimulated Raman scattering. An apparatus for reducing such gain profile variations is described which monitors optical signal perturbations and reacts by adjusting pump powers of the amplifiers and, or fast variable optical attenuator according to a pre-determined function stored in the form of constants in controller's memory. The optical signal is monitored as total power, and the power of light after passing through one or more optical filters. The light detection is relatively fast, whereby the gain profile variations are compensated by fast controlled variable optical attenuator and pump power adjustment upon the change in loading conditions.

Abstract: A reconfigurable optical amplifier is formed of a plurality of optical switches and a plurality of fiber amplifier sections to provide a switchable amplifying network. A variable pump splitter provides pump light from an optical pump source to two or more fiber amplifier sections. The optical switches and variable pump splitters are formed in a planar lightwave circuit, which may further include pump WDM combiners, variable optical attenuators, tap couplers and other optical components, and to which monitoring photodiodes and the fiber amplifier sections are coupled. A same PLC can be used for a wide variety of reconfigurable optical amplifiers.

Abstract: A fiber amplifier having two erbium doped fiber coils and a pump laser diode optically coupled, through a fiber array, to a planar lightwave circuit, is described. A photodetector array, a multiport free-space optical isolator, and a strip of thin-film gain flattening filter are attached to a side surface of the planar lightwave circuit, which has a tunable optical power splitter for variably splitting the optical pump power for the laser diode between the two erbium doped fiber coils, and variable tilters for correcting the gain tilt of the amplifier. The variable splitter and the tilters are thermally tunable Mach-Zehnder interferometers.

Abstract: A change in loading conditions of fiber amplifiers in an optical communications network causes rapid variations in the gain profile of the amplifiers due to spectral hole burning and stimulated Raman scattering. An apparatus for reducing such gain profile variations is described which monitors optical signal perturbations and reacts by adjusting pump powers of the amplifiers and, or fast variable optical attenuator according to a predetermined function stored in the form of constants in controller's memory. The optical signal is monitored as total power, and the power of light after passing through one or more optical filters. The light detection is relatively fast, whereby the gain profile variations are compensated by fast controlled variable optical attenuator and pump power adjustment upon the change in loading conditions.