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 wave control are still insufficient, with only a few functions being proposed. Moreover, some designs use metal antennas as Mie resonators to provide the necessary phase shifts, which introduce undesirable Ohmic losses and thermal effects. Here, we numerically demonstrate a set of silicon nitride (Si₃N₄) phase-gradient meta-waveguide devices based on all-dielectric silicon (Si) antennas. The designed meta-waveguide reflector operates independently of waveguide width and achieves broadband, high-efficiency and high-fidelity reflection of the TE₀₀ mode. The designed meta-waveguide Fano resonator is based on the interference between the discrete resonance TE₀₀ mode and the continuous propagation TM₁₀ mode, which 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 mode switch enables actively tunable mode-selective output. These all-dielectric meta-waveguide devices for on-chip guided wave control will expand the component library of photonic integrated circuits (PICs) and provide positive demonstrations for high-density integrated on-chip devices.