Breaking the Coupling Efficiency–Bandwidth Trade‐Off in Surface Grating Couplers Using Zero‐Order Radiation

Abstract Silicon photonics provides wafer‐scale fabrication of densely integrated photonic circuits that are enabling breakthrough applications in datacom, artificial intelligence, and healthcare. The sub‐micrometer mode size of silicon waveguides makes efficient coupling to conventional single mode fibers extremely challenging. While advanced surface grating couplers can achieve sub‐decibel coupling efficiencies, their operation relies on …