All-dielectric meta-waveguides for on-chip integration

Meta-waveguides have demonstrated unprecedented capabilities for controlling guided waves in both free space and on-chip. However, the designs for on-chip guided waves control are still insufficient, with only a few functions being proposed. Moreover, some designs use metal antennas to provide the necessary phase shifts, which introduce undesirable Ohmic losses and thermal effects. Here, we demonstrate a set of silicon nitride (Si₃N₄) phase-gradient meta-waveguides based on all-dielectric silicon (Si) antennas. The designed meta-waveguide reflector achieves robust, broadband, high-efficiency, and high-fidelity reflection of the TE₀₀ mode. The designed meta-waveguide Fano resonator achieves Fano resonance over a broad wavelength range. Additionally, the designed meta-waveguide Fabry-Pérot (FP) cavity supports compact on-chip optical sensing and information processing. The designed meta-waveguide multimode switch enables actively tunable multimode-selective output. These all-dielectric meta-waveguides for on-chip guided waves control will expand the component library of photonic integrated circuits (PICs) and provide positive demonstrations for high-density integrated on-chip devices.