The article reviews the fabrication and photonic applications of silicon-integrated lithium niobate (LN) and barium titanate (BTO) ferroelectric thin films. LN and BTO are known for their exceptional electrical and nonlinear optical properties, making them ideal for integrated silicon photonics. The review discusses the challenges and advancements in fabricating these materials on silicon, focusing on thin film integration methods, electro-optic (EO) properties, and waveguide devices. Key topics include: 1. **Fabrication Methods**: Various techniques such as ion slicing, molecular beam epitaxy (MBE), pulsed laser deposition (PLD), and RF sputtering are used to fabricate LN and BTO thin films. The emergence of LNOI technology, which involves bonding LN thin films to an insulating layer, has significantly improved the quality and performance of LN photonics. 2. **Waveguide Devices**: Different types of waveguides, including exchanged, rib-loaded, ridge, and SOI-bonded waveguides, are discussed. The fabrication processes and characteristics of these waveguides are detailed, highlighting the importance of refractive index contrast and optical losses. 3. **Modulators**: The review covers interferometric, resonator, and phase modulators based on TFLN. Recent advancements in achieving high Q-factors and low half-wave voltage-length products are highlighted, with examples of devices achieving modulation bandwidths over 100 GHz and insertion losses below 2 dB. 4. **Nonlinear Optical Devices**: The unique properties of TFLN for nonlinear optics, including second harmonic generation (SHG), sum frequency generation (SFG), and supercontinuum generation (SCG), are discussed. The article also explores the potential of TFLN in quantum photonics and integrated photonic chips. The review concludes by summarizing the current state of integrated LN and BTO photonics research and providing insights into future directions, emphasizing the potential of these materials in various applications such as nanophotonics, quantum information processing, and all-optical networks.The article reviews the fabrication and photonic applications of silicon-integrated lithium niobate (LN) and barium titanate (BTO) ferroelectric thin films. LN and BTO are known for their exceptional electrical and nonlinear optical properties, making them ideal for integrated silicon photonics. The review discusses the challenges and advancements in fabricating these materials on silicon, focusing on thin film integration methods, electro-optic (EO) properties, and waveguide devices. Key topics include: 1. **Fabrication Methods**: Various techniques such as ion slicing, molecular beam epitaxy (MBE), pulsed laser deposition (PLD), and RF sputtering are used to fabricate LN and BTO thin films. The emergence of LNOI technology, which involves bonding LN thin films to an insulating layer, has significantly improved the quality and performance of LN photonics. 2. **Waveguide Devices**: Different types of waveguides, including exchanged, rib-loaded, ridge, and SOI-bonded waveguides, are discussed. The fabrication processes and characteristics of these waveguides are detailed, highlighting the importance of refractive index contrast and optical losses. 3. **Modulators**: The review covers interferometric, resonator, and phase modulators based on TFLN. Recent advancements in achieving high Q-factors and low half-wave voltage-length products are highlighted, with examples of devices achieving modulation bandwidths over 100 GHz and insertion losses below 2 dB. 4. **Nonlinear Optical Devices**: The unique properties of TFLN for nonlinear optics, including second harmonic generation (SHG), sum frequency generation (SFG), and supercontinuum generation (SCG), are discussed. The article also explores the potential of TFLN in quantum photonics and integrated photonic chips. The review concludes by summarizing the current state of integrated LN and BTO photonics research and providing insights into future directions, emphasizing the potential of these materials in various applications such as nanophotonics, quantum information processing, and all-optical networks.