Grazing-Angle Fiber-to-Waveguide Coupler

The silicon photonics market has grown rapidly over recent decades due to the demand for high bandwidth and data-transfer capabilities. Silicon leverage well-developed semiconductor fabrication technologies combine various photonic functionalities on same chip. Complicated integrated circuits require a mass-producible packaging strategy with broadband, coupling efficiency, fiber-array fiber-to-chip couplers, which is big challenge. In this paper, we propose new approach couplers have complementary metal-oxide semiconductor-compatible structure. An ultra-high numerical aperture fiber polished at grazing angle positioned taper-in waveguide. Our simulation results demonstrate efficiency of more than 90% hundreds nanometers broad alignment tolerance ranges, supporting use array packaging. We anticipate that proposed will be able used in commercialized systems other circuit platforms, including those made from lithium niobate nitride.