A Trident Edge Coupler For Lithium Niobate Thin Film

The application of lithium niobate thin film is a hot topic now. Due to its superior electro-optic modulation properties, it has many popular applications in integrated optics. However, LN thin film's small size also produces major challenges when attempting to efficiently couple light with optical fibers. Therefore, a trident edge coupler for LN thin-film is proposed in this paper, and its performance is studied in simulation. The trident edge coupler shows <0.8dB coupling loss per coupling facet which is promising for efficient fiber-to-chip edge coupling with large fiber spot size.