Double-layer metasurface-based edge coupler for low-loss coupling between optical fiber and thin-film lithium niobate photonic chip.

ABSTRACT: Thin-film lithium niobate (TFLN) has recently emerged as a promising platform for next-generation photonic integrated circuits, owing to its exceptional electro-optic, nonlinear, and optical properties. Despite their advantages, efficient light coupling between standard micron-sized single-mode optical fibers and submicron-sized TFLN waveguides remains a critical challenge, primarily because of the mode size mismatch and limited tolerance over broad wavelength ranges. In this paper, we propose and theoretically investigate a novel edge coupler based on an all-dielectric double-layer metasurface (DLMS), designed to overcome these limitations. The DLMS structure, inspired by the optical function of two orthogonal cylindrical lenses, reshapes a Gaussian beam emitted from an optical fiber into

SUBMITTER: Zou X 

PROVIDER: S-EPMC12819391 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature