Abstract: The invention provides improved methods and systems for a precise and selective cross-talk cancellation and pilot tones deletion in optical amplifiers. The method for cancellation of cross-talk among multiple channels occurring in a traditional optical amplifier comprises: detecting tones at an input and an output of a Smart Optical Amplifier that includes a traditional optical amplifier and a Cross-talk Cancellation Unit; comparing the detected tones at the input and output of the Smart Optical Amplifier; generating destructive tones with such amplitudes and phases so as to cancel cross-talk; and eradicating cross-talk at the output of the Smart Optical Amplifier by applying the destructive tones in the Cross-talk Cancellation Unit. Eight different embodiments that correspond to different combinations of traditional optical amplifier types and the type of technology (analog or digital) used in processing and control of signals are described.

Abstract: An apparatus and method for minimizing channel gain excursion in an optical system with automatic gain control is provided. The apparatus includes a feedback control loop which dynamically regulates the target gain of an automatic gain controlled (AGC) amplifier so as to compensate for the action of the AGC amplifier to maintain a constant linear average gain without accounting for the distribution of channels that carry signals across the amplifier spectral gain profile, which causes gain excursion of individual channels. The feedback control loop measures gain of individual channels and uses these measurements to regulate the target gain of the amplifier so as to minimize gain excursion of individual channels. If required, the apparatus may be integrated into a package. In one embodiment, the method for regulating the target gain is to maintain constant gain for all channels irrespective of the number of channels that carry a signal. This method is simple and guarantees no gain excursion.

Abstract: The invention provides improved methods and systems for a precise and selective cross-talk cancellation and pilot tones deletion in optical amplifiers. The method for cancellation of cross-talk among multiple channels occurring in a traditional optical amplifier comprises: detecting tones at an input and an output of a Smart Optical Amplifier that includes a traditional optical amplifier and a Cross-talk Cancellation Unit; comparing the detected tones at the input and output of the Smart Optical Amplifier; generating destructive tones with such amplitudes and phases so as to cancel cross-talk; and eradicating cross-talk at the output of the Smart Optical Amplifier by applying the destructive tones in the Cross-talk Cancellation Unit. Eight different embodiments that correspond to different combinations of traditional optical amplifier types and the type of technology (analog or digital) used in processing and control of signals are described.

Abstract: An apparatus and method for minimizing channel gain excursion in an optical system with automatic gain control is provided. The apparatus includes a feedback control loop which dynamically regulates the target gain of an automatic gain controlled (AGC) amplifier so as to compensate for the action of the AGC amplifier to maintain a constant linear average gain without accounting for the distribution of channels that carry signals across the amplifier spectral gain profile, which causes gain excursion of individual channels. The feedback control loop measures gain of individual channels and uses these measurements to regulate the target gain of the amplifier so as to minimize gain excursion of individual channels. If required, the apparatus may be integrated into a package. In one embodiment, the method for regulating the target gain is to maintain constant gain for all channels irrespective of the number of channels that carry a signal. This method is simple and guarantees no gain excursion.

Abstract: A method and system for multi-level power management in an optical network is provided. They include three levels of control of an amplifier. The first level of control maintains the gain of the amplifier operating in automatic gain control (AGC) mode at a target amplifier gain. The second level of control eliminates channel gain excursion by dynamically changing the amplifier target gain so as to provide that the gain for each channel is within a gain ripple of the amplifier. The third level of control sets the target gains of amplifiers according to fiber span losses. The third level of control also performs pre-emphasis of channel powers by changing the power of one or more channels passing through the amplifier so as to compensate for gain ripple of the amplifier. As a result, this multi-level control of the amplifiers in the network provides an increased level of optical signal to noise ratio (OSNR), protection of network components, and stabilization of channel power in the network.