Patent attributes
A dual-drive push-pull Mach-Zehnder modulator is provided that suppresses electrical common-mode signal components using differential input in order to mitigate parasitic phase shift effects. The modulator is configured with at least two phase shifting sections with each having a respective set of diodes. Drive signals for each phase shifter are swapped by swapping two waveguide arms in which the first and second set of diodes are constructed in a particular configuration such that the electric field applied by each drive signal in the second set of diodes is the negative of what such signal was in the first set of set of diodes. As the input optical signal propagates through the first waveguide arm and the second waveguide arm, each arm independently modulates the phase which are then re-combined to provide an optical output signal with at least one suppressed signal component.
