Advances in Electro-Optical Devices Enabled by Waveguide-Based Thin-Film Lithium Niobate

Lithium niobate (LN) materials have become a key platform for constructing core optoelectronic devices such as electro-optic (EO) modulators, optical frequency combs, and integrated optical waveguides, owing to their broad transparent window, mature waveguide processes, and excellent electro-optic effect. They demonstrate revolutionary application value in light source generation, signal transmission, and intensity modulation of optical communication systems, and are hailed as the “silicon of the photonics field,” attracting significant attention from both academia and industry. Especially with the commercialization of high-quality thin-film lithium niobate (TFLN) materials, the performance of thin-film optoelectronic devices based on waveguide structures has achieved leapfrog improvements, with their loss characteristics and modulation bandwidth far exceeding those of traditional bulk material devices. This paper systematically combs the photonic properties of LN materials, introduces in detail the electro-optic effect and electro-optic modulation principle of LN electro-optic modulators, reviews some recent research achievements of scholars, focuses on expounding the preparation processes of waveguide-based TFLN, the types of waveguide-based optoelectronic devices, and the research progress of these devices, and discusses and compares the advantages and development potential of different routes.