Efficient broadband polarization-insensitive edge coupler on a thin film lithium niobate platform for single-mode fibers
Year: 2025
Type: article
Abstract: We propose a broadband, polarization-insensitive, and fabrication-friendly edge coupler (EC) optimized for efficient coupling between a 600-nm X-cut thin-film lithium niobate (TFLN) platform and a standard 9.2-μm single-mode fiber at 1550 nm. A single-layer silicon nitride (Si 3 N 4 ) waveguide structure and a three-stage adiabatic taper are employed to enhance mode-field matching and minimize propagation losses. The optimized EC achieves coupling losses of −0.546/−0.501 dB (TE/TM), polarization-dependent loss (PDL) of 0.035 dB, a 1-dB bandwidth exceeding 100 nm, and robust alignment tolerances (±2.0 μm/±2.2 μm laterally and ±1.7 μm/±1.9 μm vertically for TE/TM modes), making it highly suitable for scalable TFLN photonic integration.
Source: Optics Express
DOI: 10.1364/oe.561741
Authors: Shaobo Fang, Binzhou Hong, Shuyuan Liu, Yinan Lao, Haiwen Cai, Wei Chu
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,270
OpenAlex ID: W4409365002