Polarization Management on Anisotropic Thin-Film Lithium Niobate Platform

This review explores polarization mode hybridization in x-cut thin-film lithium niobate (TFLN) waveguides and its implications for the design of photonic integrated device. It addresses strategies to mitigate anisotropy and mode hybridization as well as approaches to exploit these effects for advanced polarization control. The review covers essential devices, including polarization beam splitters, rotators, splitter-rotators, polarizers, and polarization-insensitive components such as multimode interference couplers, directional couplers, and optical fiber interfaces. Furthermore, the review highlights their applications in polarization-division multiplexing, polarization-insensitive modulation, and advanced polarization control systems. These advancements underscore the substantial potential of TFLN in enabling polarization management and next-generation integrated photonic technologies.