An optical phase modulator comprises a cascaded array of optical resonators, wherein each of the optical resonators has an input port and an output port. A plurality of waveguides are coupled between the optical resonators and are configured to provide cascaded optical communication between the optical resonators. Each of the waveguides is respectively coupled between the output port of one optical resonator and the input port of an adjacent optical resonator. A transmission electrode is positioned adjacent to the optical resonators, with the transmission electrode configured to apply a drive voltage across the optical resonators. The optical phase modulator is operative to co-propagate an input optical wave with the drive voltage, such that a resonator-to-resonator optical delay is matched with a resonator-to-resonator electrical delay.