High-speed femtosecond laser lithography for low-loss wafer-scale lithium niobate integrated photonics

Photolithography-assisted chemo-mechanical etching (PLACE), a dedicated fabrication methodology for high-quality (high-Q) large-scale photonic integrated circuits (PICs) on thin-film lithium niobate (TFLN), has enabled the realization of diverse PICs spanning from high-Q micro-resonators to waveguide amplifiers and programmable photonic circuits. To advance high-throughput TFLN PICs manufacturing, we developed a laser lithography technique employing a high repetition-rate femtosecond laser and a high-speed polygon scanner, achieving a lithography throughput of 2.4 cm²/h and optical propagation loss below 0.1 dB/cm. System capabilities are further evidenced by the demonstration of wafer-scale fabricated TFLN photonic devices, confirming the scalability and performance of this lithographic platform.