Frequency Conversion in Periodically Poled Thin-Film Lithium Tantalate Photonic Integrated Circuits

Second-order optical nonlinear processes, such as second harmonic generation, difference-frequency generation, or sum-frequency generation, find numerous applications in laser science, quantum technology, sensing, photonic computing, and many other areas. Traditionally, bulk crystals are used for these processes, including lithium niobate (LiNbO3) and lithium tantalate (LiTaO3). However, bulk crystals face challenges, including low efficiency due to large optical mode areas and difficulty in achieving phase matching, which is essential for efficient energy transfer between interacting waves.