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 E I of an optical signal in response to a first driving voltage V I , and the second inner MZM generates a quadrature component E Q of said optical signal in response to a second driving voltage V Q . Further disclosed is a calculation unit 52 configured for receiving an in-phase component y I and a quadrature component y Q _ of a desired base-band signal, and for calculating pre-distorted first and second driving voltages V I , V Q . The calculation of the pre-distorted first and second driving voltages V I , V Q 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 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.