In a radio frequency (RF)-photonic arbitrary waveform generator (AWG), an optical carrier signal is phase-modulated using an arbitrary waveform optical phase generator (AWPOG), which may include, e.g., sequential optical phase modulators. The phase-modulated optical signal is combined with a version of the optical carrier signal to yield an optical waveform, whose amplitude varies with a phase shift introduced by the AWPOG to the optical carrier signal. By manipulating electrical inputs to the AWPOG which control the phase shift, the optical waveform can be arbitrary shaped. The optical waveform may then be converted to an electrical waveform having a radio frequency.