BaTiO3/Si-hybrid slot-waveguide electro-optic modulator

Electro-optic (EO) modulators are crucial components to generate high-speed photonic signals in the modern photonic communication system. Here we study the performance of a hybrid EO modulator employing a Si slot waveguide and a BaTiO₃ layer, where the EO effect of BaTiO₃ is stronger than that of widely used LiNbO\(_3\). We demonstrate that an appropriate design for the slot waveguide, the BaTiO\(_3\) layer, and doped Si connectors to metal contacts can achieve a low voltage-length product \(V_\pi L\) of 0.16 V cm, a wide modulation bandwidth of 50 GHz, and a small propagation loss of \(<1\) dB/cm simultaneously. These values indicate efficient use of the proposed modulator in the photonic communication system.