Very low voltage single drive domain inverted LiNbO_3 integrated electro-optic modulator

Domain inversion is used in a simple fashion to improve significantly the performance of a waveguide electro-optic modulator in z-cut LiNbO(3). The waveguide arms of the Mach-Zehnder interferometer are placed in opposite domain-oriented regions under the same, narrower and more efficient electrode, so that opposite phase shifts (push-pull effect) can still be achieved despite the arms being subjected to the same electric field. Switching voltages close to 2 V are obtained, which allow 10Gb/s modulation with inexpensive drivers, such as those used for electro-absorption modulators, which deliver driving voltages well below 3V.