A method comprising applying an In-phase (I) offset to an I component of an orthogonal pseudo-random coded direct current (DC) bias signal, applying a Quadrature-phase (Q) offset to a Q component of the orthogonal pseudo-random coded DC bias signal, applying an I dither signal to an I Mach-Zehnder modulator (MZM), wherein the I dither signal is based on the I component of the orthogonal pseudo-random coded DC bias signal, applying a Q dither signal to a Q MZM, wherein the Q dither signal is based on the Q component of the orthogonal pseudo-random coded DC bias signal, and performing arbitrary waveform generation (AWG) by modulating an analog data signal onto an optical carrier signal via the MZMs, wherein the I offset and the Q offset are selected to mitigate crosstalk between the I MZM and the Q MZM due to a finite extinction ratio.