All-Dielectric Huygens' Meta-Waveguides for Resonant Integrated Photonics

The growing maturity of nanofabrication technology has recently enabled the deployment of high-quality subwavelength nanostructures on photonic chips. Combining existing photonic waveguide technology with the paradigms adapted from metamaterials opens new avenues towards unprecedented control of guided light waves. However, developing new functionalities while preserving efficiencies and offering compatibility with current technology remains a major challenge in on-chip nanophotonics. Here, a novel silicon nanophotonic waveguide comprising a chain of resonantly forward scattering nanoparticles empowered by spectrally overlapping electric and magnetic dipolar Mie-type resonances is proposed and demonstrated. The propagation loss of the meta-waveguides in the telecom spectral range is as low as 0.4 dB mm(-1), exceeding the current record for Mie-resonant waveguides by more than an order of magnitude. Furthermore, the meta-waveguides support a negative group index over a broad spectral range of 60 nm and regions of vanishing and anomalous dispersion within the transmission band. Finally, it is shown that meta-waveguide topologies can implement compact resonance-protected waveguide bends and efficient splitters within just 320 nm propagation length. This work addresses the fundamental challenges of miniaturization, dispersion, and scattering control in integrated photonics and opens new opportunities for enhancing light-matter interactions, interfacing nanophotonic components, and developing nonlinear, ultrafast, and quantum optics resonant on-chip devices.