Abstract: Optical amplifier assembly for spatial division multiplexing (SDM) optical communication systems. Each optical amplifier assembly includes a single pump assembly configured for causing amplification of signals traveling on separate fiber paths in different directions. Each fiber path includes a plurality of spatial dimensions. The single pump assembly includes a plurality of pump sources to provide redundancy and the optical amplifier assembly further includes splitters for splitting outputs of the pump sources to amplifiers coupled to the different spatial dimensions. Different modulation formats may be used on the different spatial dimensions with different pump power being provided to each of the modulation formats. Amplifiers with complementary outputs may be coupled to average out gain deviations.

Abstract: An optical communication amplification system may include a number of amplification stages for an optical signal that includes a first optical wavelength band signal portion and a second optical wavelength band signal portion. Each amplification stage may separate the first optical wavelength band signal portion from the second optical wavelength band signal portion. The separated first optical wavelength band signal portion is amplified using one or more first optical wavelength band amplifiers and the separated second optical wavelength band signal portion are amplified using one or more second optical wavelength band amplifiers. The amplified first optical wavelength band signal portion is filtered and a reflected portion of the first optical wavelength band signal portion may be used to provide energy to the one or more second optical wavelength band amplifiers to increase the power or gain of the separated second optical wavelength band signal portion.

Abstract: Optical amplifier assembly for spatial division multiplexing (SDM) optical communication systems. Each optical amplifier assembly includes a single pump assembly configured for causing amplification of signals traveling on separate fiber paths in different directions. Each fiber path includes a plurality of spatial dimensions. The single pump assembly includes a plurality of pump sources to provide redundancy and the optical amplifier assembly further includes splitters for splitting outputs of the pump sources to amplifiers coupled to the different spatial dimensions. Different modulation formats may be used on the different spatial dimensions with different pump power being provided to each of the modulation formats. Amplifiers with complementary outputs may be coupled to average out gain deviations.

Abstract: An optical communication amplification system may include a number of amplification stages for an optical signal that includes a first optical wavelength band signal portion and a second optical wavelength band signal portion. Each amplification stage may separate the first optical wavelength band signal portion from the second optical wavelength band signal portion. The separated first optical wavelength band signal portion is amplified using one or more first optical wavelength band amplifiers and the separated second optical wavelength band signal portion are amplified using one or more second optical wavelength band amplifiers. The amplified first optical wavelength band signal portion is filtered and a reflected portion of the first optical wavelength band signal portion may be used to provide energy to the one or more second optical wavelength band amplifiers to increase the power or gain of the separated second optical wavelength band signal portion.

Abstract: An optical communication amplification system may include a number of amplification stages for an optical signal that includes a first optical wavelength band signal portion and a second optical wavelength band signal portion. Each amplification stage may separate the first optical wavelength band signal portion from the second optical wavelength band signal portion. The separated first optical wavelength band signal portion is amplified using one or more first optical wavelength band amplifiers and the separated second optical wavelength band signal portion are amplified using one or more second optical wavelength band amplifiers. The amplified first optical wavelength band signal portion is filtered and a reflected portion of the first optical wavelength band signal portion may be used to provide energy to the one or more second optical wavelength band amplifiers to increase the power or gain of the separated second optical wavelength band signal portion.

Abstract: An optical communication amplification system may include a number of amplification stages for an optical signal that includes a first optical wavelength band signal portion and a second optical wavelength band signal portion. Each amplification stage may separate the first optical wavelength band signal portion from the second optical wavelength band signal portion. The separated first optical wavelength band signal portion is amplified using one or more first optical wavelength band amplifiers and the separated second optical wavelength band signal portion are amplified using one or more second optical wavelength band amplifiers. The amplified first optical wavelength band signal portion is filtered and a reflected portion of the first optical wavelength band signal portion may be used to provide energy to the one or more second optical wavelength band amplifiers to increase the power or gain of the separated second optical wavelength band signal portion.

Abstract: An optical subcarrier multiplex system. An input data signal is jointly coded with at least one forward error correction (FEC) code before symbol mapping and before subcarrier modulation. Joint FEC coding mitigates non-uniform subcarrier performance.

Abstract: A system and method including a transmitter including digital signal processor for providing a shaped data output in response to an input data stream. The shaped data output is coupled to a modulator that modulates an optical signal in response to the shaped data output to provide a non-rectangular shaped output having channel spacing greater than Nyquist channel spacing. Providing a shaped output consistent the present disclosure mitigates the effects of non-linear impairments in an optical transmission system.

Abstract: A system and method including a transmitter including digital signal processor for providing a shaped data output in response to an input data stream. The shaped data output is coupled to a modulator that modulates an optical signal in response to the shaped data output to provide a non-rectangular shaped output having channel spacing greater than Nyquist channel spacing. Providing a shaped output consistent the present disclosure mitigates the effects of non-linear impairments in an optical transmission system.

Abstract: Methods and systems for processing an optical signal in a communication system are disclosed. The disclosed methods yield benefits for estimation and tracking of carrier phase of received signals at a digital coherent receiver. Specifically, phase ambiguity is removed by the insertion of pilot symbols into a transmitted data stream. Pilot symbols are detected from a received signal, and carrier phase is estimated for the detected pilot symbols. If carrier phase track of received data symbols was lost, a correction is applied to recover the track. Coherent symbol decoding may be used which has not been possible with prior art techniques due to the possibility of phase tracking loss.

Abstract: Methods and systems for processing an optical signal in a communication system are disclosed. The disclosed methods yield benefits for estimation and tracking of carrier phase of received signals at a digital coherent receiver. Specifically, phase ambiguity is removed by the insertion of pilot symbols into a transmitted data stream. Pilot symbols are detected from a received signal, and carrier phase is estimated for the detected pilot symbols. If carrier phase track of received data symbols was lost, a correction is applied to recover the track. Coherent symbol decoding may be used which has not been possible with prior art techniques due to the possibility of phase tracking loss.

Abstract: Methods and systems for processing an optical signal in a communication system are disclosed. The disclosed methods yield benefits for estimation and tracking of carrier phase of received signals at a digital coherent receiver. Specifically, phase ambiguity is removed by the insertion of pilot symbols into a transmitted data stream. Pilot symbols are detected from a received signal, and carrier phase is estimated for the detected pilot symbols. If carrier phase track of received data symbols was lost, a correction is applied to recover the track. Coherent symbol decoding may be used which has not been possible with prior art techniques due to the possibility of phase tracking loss.

Abstract: A WDM optical transmission system and method uses slope compensation at the transmit terminal and/or the receive terminal. The system and method may be used with modulation formats with a short pulse width and a broad optical spectrum.

Abstract: A WDM optical transmission system and method uses slope compensation at the transmit terminal and/or the receive terminal. The system and method may be used with modulation formats with a short pulse width and a broad optical spectrum.

Abstract: A WDM optical transmission system and method uses slope compensation at the transmit terminal and/or the receive terminal. The system and method may be used with modulation formats with a short pulse width and a broad optical spectrum.

Abstract: A WDM optical transmission system and method uses slope compensation at the transmit terminal and/or the receive terminal. The system and method may be used with modulation formats with a short pulse width and a broad optical spectrum.

Abstract: A hybrid Raman-EDFA provides gain equalization over the C-band and L-band. The hybrid Raman-EDFA includes a Raman section producing a Raman gain and an EDFA section producing an EDFA gain complementing the Raman gain. The EDFA section preferably includes a highly inverted, single-stage EDFA to produce the complementing EDFA gain shape. One embodiment of the EDFA section includes a high return loss termination located after the erbium fiber to receive unabsorbed pump power. Multiple hybrid Raman-EDFAs can be connected in an amplifier chain in a transmission system. The transmission system preferably provides a dispersion map including regular composite fiber spans followed by at least one compensating span of negative dispersion fibers. The Raman sections of the hybrid Raman-EDFAs are preferably coupled to negative dispersion fiber in the transmission system.

Abstract: A system and method for controlling optical amplifier pumps. A path average intensity detector is provided for detecting a path average intensity for transmitted optical signals. In response to the detected path average intensity or a variation in path average intensity, a pump parameter controller dynamically adjusts at least one pump parameter of at least one amplifier to achieve a desired path average intensity.

Abstract: A method and system by which a wide bandwidth continuous wave (CW) or substantially continuous wave composite (SCWC) pump with a flat spectrum is utilized to amplify an information-carrying signal. By using a wide bandwidth CW pump, substantially no ripple is introduced to the signal being amplified by the Raman amplifier.

Abstract: A system and method for controlling optical amplifier pumps. A path average intensity detector is provided for detecting a path average intensity for transmitted optical signals. In response to the detected path average intensity or a variation in path average intensity, a pump parameter controller dynamically adjusts at least one pump parameter of at least one amplifier to achieve a desired path average intensity.