A cascaded modulator system configured to minimize the extinction ratio (ER) of an optical output of an optical transmitter. The cascaded modulator system includes a pulse position modulation (PPM) source connected to a plurality of serially-connected Mach Zehnder Interferometer (MZIs). A variable time delay Δtd may be applied to a negative low voltage differential signal (LVDS) driving a second or later MZI of the plurality of MZIs to eliminate or compensate for one or more non-idealities in an electrical signal.