An optical modulator that includes a resonator near one arm of a Mach-Zehnder interferometer and that increases the optical length of that arm so as to introduce a phase-shift in an optical signal propagating in that arm when compared to an optical signal propagating in the other arm of the interferometer. The resonator also increases the electro-optic interaction between an electrical signal (i.e., the source of information in a modulated signal) and the optical devices (e.g., waveguides). A modulator constructed in accordance with the present invention is thus physically small than prior art modulators and requires a significantly reduced drive voltage to impart information on an optical signal.