High-Quality Optical Hotspots with Topology-Protected Robustness

Optical hotspots underpin a wide variety of photonic devices ranging from sensing, nonlinear generation to photocatalysis, taking advantage the strong light–matter interaction at vicinity nanostructures. While plasmonic nanostructures have been widely used for strongly localized electromagnetic energy on surfaces, they suffer high loss and consequently low quality factor. Resonance-based dielectric structures provide an alternative solution with larger factor, but there is mismatch between maximum values light confinement (quality factor) leakage (intensity in near-field). Here, we propose apply concept topological photonics formation hotspots, producing them both edge states corner states. The topology secures localization surface where underlying invariant shows jump, generating field hotspot simultaneous increment factor intensity. Meanwhile, it leverages good robustness fabrication imperfection including fluctuation shape misalignment. After systematic investigation comparison 1D 2D structures, conclude that promise fertile playground emerging applications require enhanced intensity spectral resolution.