Abstract: Disclosed herein is a dual parallel Mach-Zehnder-modulator (DPMZM) device comprising a DPMZM 10 having first and second inner MZMs arranged parallel to each other. The first inner MZM generates an in-phase component EI of an optical signal in response to a first driving voltage VI, and the second inner MZM generates a quadrature component EQ of said optical signal in response to a second driving voltage VQ. Further disclosed is a calculation unit 52 configured for receiving an in-phase component yI and a quadrature component yQ of a desired base-band signal, and for calculating pre-distorted first and second driving voltages VI, VQ. The calculation of the pre-distorted first and second driving voltages VI, VQ is based on a model of said DPMZM 10 accounting for I-Q cross-talk, and using an algorithm that determines said first and second driving voltages VI, VQ each as a function of both of said in-phase and quadrature components yI, yQ of said base-band signal.

Abstract: Disclosed herein is a dual parallel Mach-Zehnder-modulator (DPMZM) device comprising a DPMZM 10 having first and second inner MZMs arranged parallel to each other. The first inner MZM generates an in-phase component EI of an optical signal in response to a first driving voltage VI, and the second inner MZM generates a quadrature component EQ of said optical signal in response to a second driving voltage VQ. Further disclosed is a calculation unit 52 configured for receiving an in-phase component yI and a quadrature component yQ of a desired base-band signal, and for calculating pre-distorted first and second driving voltages VI, VQ. The calculation of the pre-distorted first and second driving voltages VI, VQ is based on a model of said DPMZM 10 accounting for I-Q cross-talk, and using an algorithm that determines said first and second driving voltages VI, VQ each as a function of both of said in-phase and quadrature components yI, yQ of said base-band signal.

Abstract: Disclosed herein is a dual parallel Mach-Zehnder-modulator (DPMZM) device comprising a DPMZM 10 having first and second inner MZMs arranged parallel to each other. The first inner MZM generates an in-phase component EI of an optical signal in response to a first driving voltage VI, and the second inner MZM generates a quadrature component EQ of said optical signal in response to a second driving voltage VQ. Further disclosed is a calculation unit 52 configured for receiving an in-phase component yI and a quadrature component yQ_ of a desired base-band signal, and for calculating pre-distorted first and second driving voltages VI, VQ. The calculation of the pre-distorted first and second driving voltages VI, VQ is based on a model of said DPMZM 10 accounting for I-Q cross-talk, and using an algorithm that determines said first and second driving voltages VI, VQ each as a function of both of said in-phase and quadrature components yI, yQ of said base-band signal.

Abstract: Component signal values are derived from component signals and fed to at least one fixed equalizer which generates equalizer output signals. The signals are fed to phase error detectors generating phase error signals. The phase error signals are combined with further phase error signals derived by further error detectors receiving signal values from further equalizers and/or the component signal values directly from sample units.

Abstract: Disclosed herein is a dual parallel Mach-Zehnder-modulator (DPMZM) device comprising a DPMZM 10 having first and second inner MZMs arranged parallel to each other. The first inner MZM generates an in-phase component EI of an optical signal in response to a first driving voltage VI, and the second inner MZM generates a quadrature component EQ of said optical signal in response to a second driving voltage VQ. Further disclosed is a calculation unit 52 configured for receiving an in-phase component yI and a quadrature component yQ_ of a desired base-band signal, and for calculating pre-distorted first and second driving voltages VI, VQ. The calculation of the pre-distorted first and second driving voltages VI, VQ is based on a model of said DPMZM 10 accounting for I-Q cross-talk, and using an algorithm that determines said first and second driving voltages VI, VQ each as a function of both of said in-phase and quadrature components yI, yQ of said base-band signal.

Abstract: Component signal values are derived from component signals and fed to at least one fixed equalizer which generates equalizer output signals. The signals are fed to phase error detectors generating phase error signals. The phase error signals are combined with further phase error signals derived by further error detectors receiving signal values from further equalizers and/or the component signal values directly from sample units.

Abstract: A method for an optical communication system and an optical communication system comprising a pump source configured to generate a pump signal having rotating polarization, a polarization sensitive receiver for receiving the optical signal having a polarization tracking cut-off frequency, wherein the polarization of the pump signal is configured to rotate at a predetermined frequency of polarization rotation and the frequency of polarization rotation of the pump signal is higher than the polarization tracking cut-off frequency of the receiver. Suitable for mitigation of cross-polarization modulation (XPolM) related effects in coherent polarization multiplexed quadrature phase shift keying (CP-QPSK) systems.

Abstract: Component signal values are derived from component signals and fed to at least one fixed equalizer which generates equalizer output signals. The signals are fed to phase error detectors generating phase error signals. The phase error signals are combined with further phase error signals derived by further error detectors receiving signal values from further equalizers and/or the component signal values directly from sample units.

Abstract: Component signal values are derived from component signals and fed to at least one fixed equalizer which generates equalizer output signals. The signals are fed to phase error detectors generating phase error signals. The phase error signals are combined with further phase error signals derived by further error detectors receiving signal values from further equalizers and/or the component signal values directly from sample units.

Abstract: Component signal values are derived from component signals and fed to at least one fixed equalizer which generates equalizer output signals. The signals are fed to phase error detectors generating phase error signals. The phase error signals are combined with further phase error signals derived by further error detectors receiving signal values from further equalizers and/or the component signal values directly from sample units.

Abstract: A method for an optical communication system and an optical communication system comprising a pump source configured to generate a pump signal having rotating polarization, a polarization sensitive receiver for receiving the optical signal having a polarization tracking cut-off frequency, wherein the polarization of the pump signal is configured to rotate at a predetermined frequency of polarization rotation and the frequency of polarization rotation of the pump signal is higher than the polarization tracking cut-off frequency of the receiver. Suitable for mitigation of cross -polarization modulation (XPolM) related effects in coherent polarization multiplexed quadrature phase shift keying (CP-QPSK) systems.

Abstract: Component signal values are derived from component signals and fed to at least one fixed equalizer which generates equalizer output signals. The signals are fed to phase error detectors generating phase error signals. The phase error signals are combined with further phase error signals derived by further error detectors receiving signal values from further equalizers and/or the component signal values directly from sample units.