A dual parallel Mach-Zehnder-modulator, DPMZM, device comprising: a DPMZM, said DPMZM comprising first and second inner MZMs (20, 22) arranged parallel to each other, the first inner MZM for generating an in-phase component E I of an optical signal in response to a first driving voltage V I, and the second inner MZM for generating a quadrature component E Q of said optical signal in response to a second driving voltage V Q and a calculation unit configured for - receiving an in-phase component y I and a quadrature component y Q of a base-band signal, and - calculating pre-distorted first and second driving voltages V I, V Q based on • a model of said DPMZM accounting for I-Q cross-talk, and • using an algorithm that determines said first and second driving voltages V I, V Q each as a function of both of said in-phase and quadrature components y I, y Q of said base-band signal, wherein the first and second driving voltages V I, V Q are pre-distorted as compared to driving voltages devised for an ideal DPMZM without I-Q crosstalk, such as to mitigate the adverse cross talk related effects on an output signal modulated by said DPMZM device. a DPMZM, said DPMZM comprising first and second inner MZMs (20, 22) arranged parallel to each other, the first inner MZM for generating an in-phase component E I of an optical signal in response to a first driving voltage V I, and the second inner MZM for generating a quadrature component E Q of said optical signal in response to a second driving voltage V Q and a calculation unit configured for - receiving an in-phase component y I and a quadrature component y Q of a base-band signal, and - calculating pre-distorted first and second driving voltages V I, V Q based on • a model of said DPMZM accounting for I-Q cross-talk, and • using an algorithm that determines said first and second driving voltages V I, V Q each as a function of both of said in-phase and quadrature components y I, y Q of said base-band signal, wherein the first and second driving voltages V I, V Q are pre-distorted as compared to driving voltages devised for an ideal DPMZM without I-Q crosstalk, such as to mitigate the adverse cross talk related effects on an output signal modulated by said DPMZM device. - receiving an in-phase component y I and a quadrature component y Q of a base-band signal, and - calculating pre-distorted first and second driving voltages V I, V Q based on • a model of said DPMZM accounting for I-Q cross-talk, and • using an algorithm that determines said first and second driving voltages V I, V Q each as a function of both of said in-phase and quadrature components y I, y Q of said base-band signal, wherein the first and second driving voltages V I, V Q are pre-distorted as compared to driving voltages devised for an ideal DPMZM without I-Q crosstalk, such as to mitigate the adverse cross talk related effects on an output signal modulated by said DPMZM device. • a model of said DPMZM accounting for I-Q cross-talk, and • using an algorithm that determines said first and second driving voltages V I, V Q each as a function of both of said in-phase and quadrature components y I, y Q of said base-band signal, wherein the first and second driving voltages V I, V Q are pre-distorted as compared to driving voltages devised for an ideal DPMZM without I-Q crosstalk, such as to mitigate the adverse cross talk related effects on an output signal modulated by said DPMZM device.