Variable optical attenuator on the thin-film lithium niobate platform

Thin-film lithium niobate-on-insulator (LNOI) has revolutionized modern optical communications, offering unparalleled electro-optic bandwidth and low propagation loss, making it a leading platform for the next-generation optical networks. However, the absence of key functional components, such as variable optical attenuators (VOAs), has limited the full deployment of LNOI in optical communication systems, where dynamic optical power control is essential. In this work, we propose and experimentally demonstrate a VOA based on the LNOI platform. Our optimized device achieves high attenuation with low insertion loss and a compact footprint. These results represent a significant advancement in integrated LNOI optical components. The demonstrated VOA offers excellent performance and holds strong promise for enabling reconfigurable, high-speed photonic integrated circuits in future optical communication systems.