Towards high quality transferred barium titanate ferroelectric hybrid integrated modulator on silicon

Silicon photonics is currently the leading technology for the development of compact and low-cost photonic integrated circuits. However, despite its enormous potential, certain limitations, such as the absence of a linear electro-optical (EO) effect because of the symmetric crystal structure of silicon remain. In contrast, barium titanate (BTO) exhibits a strong Pockels effect. In this study, we demonstrated a high-quality transferred barium titanate ferroelectric hybrid integrated modulator on a silicon-on-insulator platform. The proposed hybrid integration of BTO on silicon Mach-Zehnder interferometers exhibited EO modulation with a VπL as low as 1.67 V·cm, thereby facilitating the realisation of compact EO modulators. The hybrid integration of BTO with SOI waveguides is expected to pave the way for the development of high-speed and high efficiency EO modulators.