Extreme Light Confinement Mediated by the Transverse Kerker Effect

Abstract

Abstract Dielectric nanoparticles can be engineered to scatter light predominantly in the transverse direction, perpendicular to the incident plane wave’s propagation direction, a phenomenon known as the transverse Kerker effect. Although complete cancellation of forward scattering from a single object is forbidden by the optical theorem, we show that a single photonic mode can provide an ideal transverse Kerker effect. When combining several nanoparticles to form a metasurface, the mode evolves into an accidental bound state in the continuum. This enables polarization-independent quasi bound states in the continuum whose quality factors are tunable without symmetry breaking. We experimentally demonstrate our concept in the visible, achieving the first polarization-independent bound state in the continuum without Brillouin-zone folding. These modes maintain large quality factors over a broader region of momentum space than conventional bound states in the continuum. Our results establish a platform for realizing ultranarrow resonances free of conventional design constraints.

The authors' abstract, as published at the source. Nano Letters, 2026 · DOI ↗