Highly Efficient and Differentially Driven Thin-Film Lithium Niobate Modulators Based on Reversely-Poled Arms

A novel structure with reversely-poled arms is proposed on the X-cut thin-film Lithium Niobate platform. A highly efficient and differentially driven phase-shifter can be achieved with a VπL of 1.37 V.cm (calculated to be equivalent to widely used single-ended push-pull scheme) and neglectable excess optical loss. A differentially driven modulator is demonstrated with 75GHz EO bandwidth and Vπ of 2 V.