With the rapid development of broadband centers, cloud-based services, the Internet of Things, and 5G services, network traffic is growing at a vigorous rate, which requires optical communication networks with higher capacity and lower power consumption. As the building block of optical communication networks, the function of the optical modulator is to realize the high-speed conversion of information from the electrical domain to the optical domain, and to convert data transmission from cable to ultra-low loss fiber. Lithium niobate (LiNbO3, LN) has been the dominant material platform for optical modulators widely used in optical fiber communications due to its excellent physical properties, such as its high electro-optic (EO) Pockels coefficient, low optical absorption, high intrinsic modulation bandwidth, and long-term material reliability. However, commercial LN modulators rely on titanium-diffused or proton-exchange waveguides. Such weakly confined optical waveguides are not beneficial to achieving strong electro-optic interaction. In the issue, such modulators have low modulation efficiency (~10V·cm) and large device sizes.